Building a Steel, Fred Murphy!

[chugalug]

I've considered cutting up Chug a few times because of goof-ups .but figured if I had problems with it -could dig frog pond in my yard,put the Bo-Jest in it and turn it into a guest cabin.would make for some good conversation starters.

[electric tug]

HAHA, yes it sure would make a good conversation piece. I like the Bo Jest, great design. I will run off to your posts to see how it is coming along. But I gotta admit, for certain things, I am perfectionistic, such as having an even and straight keel.
Sometimes I wish I had done a bo Jest. low hp, good cruising ability even a micro live aboard.

The FM "math" is like this:

800.00 cdn to move it as it is. Moving it means possibly and probably warping the whole boat.

It means I would need to cut the stem or attach longer legs to fit the strong back on the tilt and load.
The stem enters the ground, I had to dig a hole in the ground to fit it, since the stem is longer than the strong back(another error of mine not having long enough legs, but I worked directly from the plans,...)

further it requires some steel welded to it to strengthen it, for the move, I have to have it out of the build area, no later than may 31st and there is still 4 ft, yes 4 ft of snow on the ground. It will be mid April before thats gone which doesn't give me a huge window...

the new keel and frames cut by the shop was quoted about the same price*500.00 + about 300.00 for the keel pieces I need.

I have the stem, the stern post, the stringers, the gantry, the strong back, and some frames which would come with me. I can reweld everything up- thats not an issue. But if the hull is even twisted an inch out it really throws the boat out, and is probably impossible to re-align, since what direction would the boat be twisted in?

even though that doesn't seem like a lot i dont think i want to risk twisting the hull. It might be completely fine...but its a risk.

I think after all the reading of my own posts, the decision is that I can salvage what I can, cut up the bad stuff, and then move whats left.
the frames and keel parts that would need to be replaced brings it to about 800.00 which is the cost of the boat being moved. It solves the keel issues, and it also makes a more accurate build, I do not need the plaz and compressor, big savings there, and I can have the boat ready to plate by summer.


Going without a plaz, and using a shop gives me almost perfect frames cnc cut , no steel prepping for setup since the pieces would be perfectly mitered. I can simply fit and weld, and literally, if I had the frames we are talking about two days to have it all on the strongback again. The stiffeners are now cut to the proper length and the keel took me one hour to weld up and about an hour to place into position with the help of three guys. When welding in my shaft log It is also possible I warped that too.

I admit I was not careful enough and a little impatient in building it, and I will not make that mistake again.

Anyway the shaft log appears ok, but looking at it from the side it appears to dip which could be an optical illusion. The shaft log was 40.00. No big deal. The strongback also might be an issue getting it on and off the truck. they use a winch to pull the whole framework onto a tilt and load.

So in the end, i spend little time getting the shop to cut it all out, I have the other pieces ready to go, I bring the strongback, gantry, the good frames, the parts of the keel and the stringers etc., have them ready to go, then just jigsaw it all back together.
I think this for me at least solves all my issues, barring the same welding problems. The downside is that I had the boat quite far along and it is possible i might make the same mistakes with weld distortion. but I will be far more careful this next time.

I cant wait ti get everything ready to go. One last thing- there are other things I want to fix. The round bars are not bent properly, I used a jig system and they turned out terrible, not being symmetric at all, on either side so i am looking forward to having a more symmetrical vessel.

also I will be waiting until the boat is finished until i get an engine. I have made this mistake twice now. so its time to learn from this lesson.

I will increase the shaft angle a degree or two giving me more clearance, and I will align the frames on the strongback better, in the next build. I learned a lot. I did in fact mis-space two frames, it didnt hurt the boat but as I said Im perfectionistic about all this.
This gives me a redo , and i know the boat will do what I need in the coming years. It is a very well designed boat. It just had a few issues on the plans, but I know now I can work around that.
Despite all those issues, it still wasn't too bad. The keel has a bend in it, so i doubt it can be fixed. It may track to port a little and that would drive me nuts...but with the new keel, i can be assured of good tracking.
I know many here might just have it moved, but I have a lot of corrections to do, and to use the shop and forget a plasma cutter, makes the most sense for me both with time and money.

oh BTW, i plan to document all of this on youtube. so pls keep an eye out here for my updates, and I will post the vids when they are done.
Doug

[Bill Edmundson]

I haven't read all of this thread. I know you said you are a perfectionist. But, if the keel line isn't perfect, Who cares? This is a hull speed boat. Porposing won't be an issue. She's not a trailer boat. No one will see it. And, it won't hurt performance. Sit back enjoy it and have a glass of wine or a cold beer!

Bill

[electric tug]

HI Bill,
Thx for the reply. Glad to see you around and following my progress. It took me six months to get over my discouragement and rethink everything, to see what would happen. I guess I am slow at "miraculous recoveries".

Yes there is more to it than that. I wish it were more simple, but there is the matter of some frames not being correctly set up, the shaft log may be warped a little, although its hard to tell. The boat MUST be moved, so it might twist the boat and then its really messed up.

I do wonder if the keel which is really quite large wouldn't cant the vessel to port, like a car that has improper alignment, its annoying. I just cant believe that large a skeg like that would not affect tracking, but it is possible it wouldn't. Im not sure I want to risk it. The round bars are also pretty deformed, and I know that many would say that the plating covers all that up- and no one sees the keel, but -I would know.

I will however sit back and have a nice glass of lemonade-(i dont care for alcohol) and look at my boat project take shape this summer, on nice evenings. I loved doing that last summer after a hard days work. it was so nice to sit back and look at your work coming into 3d in real life.
Whatever happens, I just cant give up. I have tried... I get this sick feeling in the pit of my stomach thinking of throwing away the whole boat. I will fix it, and I guess learn from it...its the only real option despite my newfound love of wood, or composites, and all the other inherent issues. it comes down to the fact that there is no perfect boat...

best
Doug

[Bill Edmundson]

Doug

Have a glass of lemonade. Whatever it is, if you can build it the first time... You can fix it, better! I know that!

Bill

[electric tug]

The deck camber (not really that hard to do) makes the deck stronger, and steers water away from any hatches and doorways towards the scuppers.

Doug

Slug,
if you read my last three posts, it explains, I am back at the Fred in Spring. as i may have mentioned before, when it comes time to actually cut the boat up I get this sickening feeling in my gut, and I am unable to lift the grinder to the hull...
so I must forge ahead. I wanted to mention after reading your posts a while ago, that for what its worth, I think your advice is good, and i will actually use a cambered deck after all, as per the plans but without the raised after deck which houses the rudder, which is duplicating the original FM. So wanted to say thanks, for your post before, and it got me to thinking about it, and I realized, that, doing the cambered deck would actually just look better and be easier in the long run since I dont have to redesign anything. I will just plate it in wide strips to handle the compound curvature, it does add some engine room to do it proper.
hope to have you in on more conversations in the future. Btw, I plan on making some youtube vids of my build. Ill post when this happens. hope this email finds you well and in good health.
p.s. how did your tug do this year? I thought i saw it for sale somewhere online? I hope you keep it, it sure wold be nice to see it someday...if your still in Port Colborne?

[electric tug]

e'Tug, p'bill, Cambered deck beams are an elegance of shape like the sheer of the tug here. They're not absolutely needed, but do add to the decks' lines and shape as an aesthetic and drying out as they drain from just a rain squall.

A few inches of camber in this small a build would normally be rolled or pressed not flame/plaz cut because the cold forming methods will leave the frames 'still' but cooling from a hot cut almost always results in further shape changes from contraction. If the notches for deck longs are added to the hot cut methods; most cambered decks frames become almost unpredictable- and need reforming to some minor degree due the combined heat of the arcs/camber cuts PLUS the notches for longs.

So in shallow cambers on smaller hulls (<or=30' LOA roughly) cold forming is much more reliable, usually faster and involved less expensive equipment.

The "Whale Back" shape of the deck following the sheer in one curve while having transverse curvature does form a tiny amount of compound curvature. Usually when fitting deck plates of this type, wholly dependent on the sheet sizes used, there is a very small hourglass curvature if the deck seams are transverse. If the seams are longitudinal (?) then the deck panels are slightly blubous in their length.

The amounts for a few inches of camber in this size boat are less than 1/2" in 10' transverse or less than 3/4" in 12-14' deck panels run fore and aft- assuming you're building an entire surface? ( I don't think that's the case here?) A simple method of battening these of laying plates on the the deck frames and marking from below usually gives the shapes' curves arc depths- that is the depth of the chord's curvature over the full length of the seam.

However, in most cases the house, trunk and cockpit so interrupt these surfaces (decks) that the amount of compound is never seen by the builder, each deck panel is simply fit to that given area without any fully transverse areas- and the amount of compound in the tiny fore deck is negligible.

I did a 52' steel crabber in the 1970's designed by Ed Monk (Sr.) of Seattle with owner/builder here in the Cook Inlet, in Alaska. The entire after deck area, designed to carry stacked crab pots, was cambered 4.75" in her 14 beam and was plated with 1/4" steel. The deck frames followed a 13" cup in the sheer that was 31' long with 5-1/2" deep transverse frames 2' OC and 2x2x1/4" T longs notched into the deck longs inverted. I cut them with an OA torch on a track carriage; then had to make a press frame with a hydraulic jack to individually bend them back to a uniform camber and curvature before they could become part of the ring frames for the boat.

When I decked the working surface over the crab tank and lazzarette the plates were all 4' x 10' x 1/4" and both the ends and the sides of each plate had to be curved very slightly to fit into weld seams. This Whale Back deck shape was compound but still had pretty small plate adjustments (full length curves in both directions) as long slow curves in order to fit up for welds, while the panels laid to the framing below.

I'd say this small tug would deck without much effort to these curves, given the deck is probably broken into smaller areas and not one big expanse??

Electric Tug, please don't forget the electric nibbler tool. This cold cutting AC electric tool can be found in industrial capacities to handle much thicker steel than your scantlings call for. The edge left is serrated but can be sanded dead smooth with a 40 grit flap sanding pad in a few strokes so this cold cutting sheet seam or edge tool is very much worth an investigation.

Cheers,
Kevin Morin
Kenai, AK

Hi Kevin,
I reread your post about camber, and I think you know a hell of a lot more about building than i do. I in fact never did look at your other posts until now only to find out you are like some god of aluminum and metal boat work... I probably should have paid more attention to your posts, but did take it all in. I was wondering, would using long strips make it easier to deck the cambered hull? or would you advise going with athwart ship seems when plating? I will indeed just do it to the plans but omit the raised stern section making the hull more like the original FM. also, would it make much difference if I welded up the plate with my standard 200 amp inverter stick welder(my great workhorse all season outdoor welder, which has a very smooth arc) or invest again in a mig and pick my days outdoors to weld? I would be welding up mostly 1/8th " steel plate form the FM plans both on deck and the hull.
I was thinking my little inverter welder could be fine is using 3/32nd or smaller rod for the seams.
pls join in and offer advice anytime. I also was wondering if you would mind reading my last few posts since I was going to cut up the build, i have been unable to lift the grinder to the boat, my arms and hands do not seem willing, and the pit of my stomach feels like a massive kidney stone when i try. so i am forging ahead(again). this time i will just buy a smaller engine, and not worry too much about prop sizes or large engines. i just want to cruise, and maybe something like a 33 hp lister would be fine. I will just use any gearbox close to 3:1. I did sell my Volvo because it did not fit in the engine room space and the shaft angle was wrong. but in the previous posts I have mentioned how I am going to correct that and what my options are.
btw your boat designs are lovely. especially the aluminum ones on your posts in "metal boats".
best
Doug

[electric tug]

Doug

Have a glass of lemonade. Whatever it is, if you can build it the first time... You can fix it, better! I know that!

Bill

HI Bill,
i Juts looked over your Tahoe build...wow!
what else is there to say.
btw thanks for taking the time to respond earlier.
do you have any youtube vids of it running? how did it perform? looks like it was an easy install too? where di you get the wood?

best
Doug
p.s. It is funny because after work on the boat last summer, i would sit in a chair, grab a cold 'lemo'(short for lemonade), and dream while watching my hull come together into 3d. what a feeling! cant wait to do it again. this time, I may by a cooler like yours even!

[Bill Edmundson]

Doug

There are some videos on this site from a couple of Gatherings back. I think I bought the ply from Noah's for the Tahoe. The Bartender ply came from Homestead. Most of the lumber came from Hardwoods of Alabama. H of A no longer sells direct to the public.

BTW: The Tahoe runs great. It has some V at the transom and a deep sharp forefoot.

Bill

[Kevin Morin]

Doug, thanks for the kind words about my work, I did build full time from the late 1970's til 1989 and then part time (on and off odd projects) since then. The one 25' shown most in my posts is because I had the opportunity to see what pictures of my work was worth most of the hundreds of other projects came and went without any pictures, so the most recent boats have the most pictures.

What I try to share in most of the threads is well known to almost all full time builders. I'm only unique in that I take time to try to illustrate the ideas and simplify the work in an attempt to bring basic foundational skill building exercises to others. Any semi-retired builder knows all that I'm showing but isn't necessarily inclined to take time to make the information useful to others. I like to do the sketches and enjoy encouraging others to learn to build their own boats. I'm pretty sure that what seems like lots of knowledge is more a case of someone willing to take time show widely held knowledge but not often shared in the way we're here at Glen-L Forum.

That all goes to show few of my countless mistakes! If you'd done many boats, you're learning curve wouldn't be a steep- we all begin from the same 'white page' or Blank Sheet if you're following my terms? There is little reason for the new builder to beat themselves up over their learning stages. I just don't have many pictures of my millions of mistakes - just some of my work AFTER I'd made them- learned from those mistakes what to avoid and therefore a pictures of my later work may mistakenly leave the impression that I always been able to build to this level? Not a true impression, believe me.

As to your project, my take is that you know you're not satisfied with your own work. Therefore you will never become satisfied with that work and it should be taken down. This will allow you to move the parts and retain 100% of them for what use they may be in the future? That is huge wide topic of use. Yes you might get the frames NC cut (if you have the NC tool path cut files?) but the old frames may work to build countless supports, coamings, temporary pieces for tack up, and on and on.... don't trash it- keep it 100% regardless if those pieced go into the new boat.

Next, point I get from reading your posts is that you may have begun work doing one section or another of permanent work before you were ready - by your own description. If you can't cut the way you want- A) don't cut permanent pieces until you can so B) practice cutting - or re-tooling until you can do what you need to satisfy your skill and work level requirements. Let's do this with a car on the road?

You're rolling down the road between the two lines - dashed yellow on the left and solid yellow (or white) on the right. Things are OK- you're on the road and "in between the lines". Now you look up and you're not between the lines - if your left wheel is the left of the dashed line you may just make and adjustment with the steering wheel and back you are "in between the lines". But... what if the left wheel is the right of the right side line? Well you'd better put on the brakes and quick. You've described a build where you kept driving while you were in the ditch !!! not even on the road, but you kept driving!

Don't cut, fit, weld or do any permanent work if you do not have the skills to bring to that work that will allow you to do satisfactory work. Otherwise you'll be where were a few months past- giving up the entire project.

What I suggest is that you use the lessons you've experienced to help guide the build. I'd cut the frame's apart, retain 100% of the metal don't try to move in tact, get to the new location and as you have time- plan in WRITING, the most neglected work technique for many low hour builders, what to do next time.

If the move is the big event to accomplish,do that and spend all the time free between now and when that is done - planning. # 1 Make a list of the problem areas, then in your own words write down the procedure you Should have followed? #2 What is missing from you doing what's in #1? #3 those are the items to concentrate on before yo begin again.

So if you didn't layout or cut the framing elements (any of them) to your own satisfaction(?) what are you going to do this time to make sure you're satisfied? That could include having them NC cut, or hiring a local shop to do some shear and brake work, or a local craftsman who has a portable welding service to come to the new work site and use his plaz torch for a few hours- and it also includes you considering other tools? For example, did you know that a hand held 8A motor electric jig saw (Bosch for example) will cut 1/4 steel as well and as accurately as it will wood? (Slower - true) So this example is to suggest that you list your own self-diagnosed problems, and plan a solution.

Be honest with yourself- and then if you're doing the work make sure you have the tools and skills up to the level needed BEFore you cut permanent parts to your boat's frame.

The day after Thomas Edison's huge million dollar lab burned down, someone asked him what he was going to do? "We'll start rebuilding in the morning." Don't be sentimental over a pile iron, strip it down, haul to the new site and "Start rebuilding in the morning." Only look back for education, don't look back and beat yourself up! We all learned by making mistakes, you've made a few- learn from them- now: build your boat.

I'd be happy to try to review any work methods that may remain a question in your mind, I did build a 52' steel crabber here in Alaska from plans by Ed Monk (Sr.) that was stretched from 48' to 52' feet and so I have a little steel boat building experience. I've welded steel since the 1970's on an off in various shops and offshore platforms so I have a little background there as well.

Cheers,
Kevin Morin
Kenai, AK

[Kevin Morin]

Doug,
I don't think the long strips on deck idea is going to result in a very smooth deck- the long seams of the hull- where plates are at an angle to one another weld up in a different manner that long flat butt seams will. So I'd prefer to build with the deck seams bent on a transverse camber- then welded on sheet material stressed to that camber so the weld distortion was minimized by the conflict of the weld contraction with the tacked up camber stress. This combination will minimize the final deck seams heat/contraction distortion when compared to long seams running fore and aft.

If I were welding a small steel boat, I'd want to use MIG with small wire- say 0.023" or 0.030" wire for 1/8"-0.125" hull sheathing. The reason I'd want to stay away from stick welding is the speed of transfer of the weld is so slow... the parent metal will build up much mUch MUch more heat of expansion with the longer time of the arc for any given seam/weld. Therefore it follows that there will naturally be more contraction from the greater heat of expansion, and that means the work to keep the hull fair is harder to do with slower welding procedures.

So, MIG for me, and as high a speed travel with as small a weld bead cross section as I can put down. I'd even use guides, fixtures, slides and other hand guide devices and fixtures to help me be steady and even movement as I tried to get faster and faster uniform travel speeds using small MIG wire.

Welding outdoors with gas covered MIG is done by tenting. Let say you're getting ready to weld a 4" frame section together? Instead of bothering with a full size boat tent, just make a little 1/2 phone both like you'd use to start sprouts in a "hot frame" in the spring. This can be plastic pipe, not even glued since it press fits most often. The tarp on the very top can be transparent or translucent and the sides can be canvas or welder's cloth so you don't light yourself afire! The light comes in the top so you grab the shield and pull into over the weld, pick up the torch with your head inside and weld that single weld.

Move on.. no need for a shop if the latitude is not freezing, but this wind screen allows fully covered welds without. On the North Slope and every where from there to Texas, "TIG tents" are used over pipe line joints. Just make yourself a small three sided version with a flap side you can move aside to put your shoulders into and weld away. All you need is to keep active air movement off the cover gas for a few seconds.

For hull seams it would be nice to have a full size tent- but the gantry could be tented and roll along with your work and keep you from having to build a full tent. Not saying this would work if you're in a raining location- you'd still have to dry out the weld, but as to wind and gas coverage- no big deal you can make a light portable shield and have all the gas coverage you'd have in the shop.

Cheers,
Kevin Morin
Kenai, AK

[electric tug]

Doug, thanks for the kind words about my work,You are most welcome Kevin, I will attempt to respond to the key points in your generous responses...
Yes, I absolutely will keep it, I will take that advice, to keep my boat parts even if not used. They are worth it


As to your project, my take is that you know you're not satisfied with your own work. I may not have been very clear on this Kevin, so my mistake if there was any confusion. What I wanted to impart was that there were things about the project that i wasn't happy with. But much of it I was. I will write down the things as you suggested later in this message... Therefore you will never become satisfied with that work and it should be taken down. I think what i will do, is to cut up the boat ,keep the pieces that work, and replace the ones that didnt, redo the boat taking into account what you have mentioned... Yes you might get the frames NC cut (if you have the NC tool path cut files?) but the old frames may work to build countless supports, coamings, temporary pieces for tack up, and on and on.... don't trash it- keep it 100% regardless if those pieced go into the new boat.Great advice Kevin and I am taking it. I will be NC cutting the frames and probably the center portion of the keel. I can avoid buying a plasma cutter for this. I know many would say buy a cutter anyway, but I am not rich, and I really cannot justify buying a 2500.00 outfit for a one time project. I can do a lot of farming out with better equipment and more skill for that amount.so it just makes sense to me. in doing the boat to its present stage I used the plasma cutter for only the frames and some of the slots for the round bars, thats it. all the rest was done with the grinder, in fact I did my frames with the grinder until I bought my cutter, and finished them with it. the keel was cnc'd, and I was very happy with it!



Don't cut, fit, weld or do any permanent work if you do not have the skills to bring to that work that will allow you to do satisfactory work. Otherwise you'll be where were a few months past- giving up the entire project. I also wasn't too clear perhaps on this. I am actually pretty confident with my welding skills, that wasn't the issue, it was certainly to do with "the car" idea. I was in a hurry, and building a boat is a lesson in patience. which i plan on following in setting up the boat when the time comes. I can weld quite well, even at a pro level for certain things like flat and possibly downhill positions, its just that in some cases I followed the plans, and the methods described did not work well for me. perhaps i just didnt take the time?..i.e. when i did the round bars, I used a jig system, the plans mentioned but it really did not work very well. I did however not follow the system exactly, because i felt much of what was explained was redundant. Thats why nest time, i will be having the steel fab company roll my round bars. this is the greatest source of problems in the build. 1. the problematic faring of these bars, and 2. the frame set up was doen much too fast. the welding was not the issue. I have two frontt frames which are not aligned perpendicular to the strongback and the keel was not template. It was taken off the plans by using a set of calipers, and thats one of those things I will do differently. also one frame got cut a slight bit lower than it should have and the keel, because it was not template, did not fit perfectly(there is my perfectionism again... . In general the boat could be built as is, and the plate cover up many of those errors, but you are correct i could not live with it, i want it to be the best i can do, and I CAN do better in the setup and in the build process.My welding i am happy with, although i still cannot figure eout how my keel warped, as i am certain i did veverything properly in the execution of the weld sequences...(scratching head)

What I suggest is that you use the lessons you've experienced to help guide the build. I'd cut the frame's apart, retain 100% of the metal don't try to move in tact, get to the new location and as you have time- plan in WRITING, the most neglected work technique for many low hour builders, what to do next time.Once again Kevin I am going to take your advice fully here. i will write it down and then have a guide to follow. it makes sense.



So if you didn't layout or cut the framing elements (any of them) to your own satisfaction(?) what are you going to do this time to make sure you're satisfied? Thats easy- first i would build one frame at a time , by drawing out one frame at a time. I found that doing the whole frames on one board with all the intersecting lines, was confusing. so i would lay out and weld up one frame from one pattern of one frame . then erase the lines and do the next one. I also will make sure I have the proper set up levels as that was an issue and I had to redraw them. somehow I made the mistake of putting the setup level lines 8 inches instead of 12" from the DWL. it cost me a lot of time, but doing a single frame form a single pattern makes it easy to do this. I would then make sure I use a laser level, right from the start to align my frames, which i used only a string and a spirit level prior. I will template the keel as suggested in the plans, and have the fab co cut that out for me.

... For example, did you know that a hand held 8A motor electric jig saw (Bosch for example) will cut 1/4 steel as well and as accurately as it will wood? (Slower - true) So this example is to suggest that you list your own self-diagnosed problems, and plan a solution.Kevin, i did try this but my jigsaw vibrated so badly. perhaps I used the wrong blade?? what would you recommend for a blade and saw for this? I can invest in a steel cutting circular saw? But I am not sure they can cut any radii cuts? I would use a jigsaw, I have lots of time. I figure a grinder with thin cut off disks does it faster and easier?


[/color]
The day after Thomas Edison's huge million dollar lab burned down, someone asked him what he was going to do? "We'll start rebuilding in the morning." Don't be sentimental over a pile iron, strip it down, haul to the new site and "Start rebuilding in the morning." Only look back for education, don't look back and beat yourself up! We all learned by making mistakes, you've made a few- learn from them- now: build your boat. Kevin, thank you for the encouragement, I needed to hear that, and thats what I will do, just start tomorrow, it is no big deal when i thin k about it. life is too short to "not try again" I will make it happen, what I know for certain now is, I cannot not do it, because it makes me sick to try to cut the boat up for scrap. make sense?

I'd be happy to try to review any work methods that may remain a question in your mindI would be very grateful for some advice here and there if thats ok with you?Cheers,
Kevin Morin
Kenai, AK

[electric tug]

.

If I were welding a small steel boat, I'd want to use MIG with small wire- say 0.023" or 0.030" wire for 1/8"-0.125" hull sheathing. The reason I'd want to stay away from stick welding is the speed of transfer of the weld is so slow... the parent metal will build up much mUch MUch more heat of expansion with the longer time of the arc for any given seam/weld. Therefore it follows that there will naturally be more contraction from the greater heat of expansion, and that means the work to keep the hull fair is harder to do with slower welding procedures.

So, MIG for me, and as high a speed travel with as small a weld bead cross section as I can put down. I'd even use guides, fixtures, slides and other hand guide devices and fixtures to help me be steady and even movement as I tried to get faster and faster uniform travel speeds using small MIG wire.Kevin, I used a small stick inverter welder, it is terrific, with an incredibly smooth arc and 200 amps capable. The guy I called about buying a Mig said the mig would not work even with multiple passes on heavy 1/2inch plate such as in welding up the three sections of my half inch keel?...but I am questioning this, wouldn't a 180 amp using the flux core do this easily? ...but before i go buy that, could the inverter stick welder with thin sticks i.e. 5/32 rod or 1/16th rod work as well? the inverter types have less heat, and less distortion. I can get an inverter mig which i did have once and it was amazing, but if possible i would like to avoid the outlay of the mig, could this 200 amp inverter stick work? it is a good unit, made by Everlast? pls advise. it wold save me close to $1000.00!

For a decent budget mig, what would you recommend? I have 1000.00 to invest but thats the limit, which is why i wanted to use the inverter stick welder...thanks in advance.

Doug




.

Cheers,
Kevin Morin
Kenai, AK

[Kevin Morin]

Doug, lots of ground to cover here. I"ll just remark that MIG vs stick is about speed and distortion control. If you've already seen some contraction distortion in the keel assembly? (inferred from my reading of the previous posts??) then.... I'd say it was time to consider faster travel and less net heat.

There is not relation to the type of power supply to the heat of a weld. Energy is energy- BTU is BTU what makes a difference is the welding time and the size of the welds added- that is all. If you weld a large slow weld, more energy is used -and conversely if you weld a fast thin bead less heat energy is imparted to the metal.

The type of power supply CV/CC/Stick only or MIG is not the factor- it is solely the time that heat is added to the metal -collecting or adding net collected heat that makes the difference. Not all small MIG systems will do the job, I haven't looked in the market for a long time, I'd have to do some reading to see what to suggest. Nothing here in this post suggests one system over another.

Glad to hear you realize the project is not a bust, may need some tuning but you sound like there are lots of pieces that still useful- and you'll conserve those.

Last, if you found a grinder more accurate than a jig saw- there are some extreme watermelons to apples comparisons going on!!! A grinder and cut of disc is too crude a tool for me to even discuss. I'm not sure you're using a quality jig saw? and I don't know the blades but I have some cutting with saws information posted on the Work Methods thread near this one - if you'd take a look you'll see that circular saws can cut curves perfectly well, that jigsaws are very useful for good control and that marking and blade view are all critical to metal cutting with non-flame or arc tools.

Cheers,
Kevin Morin
Kenai, AK

[slug]

Kevin; When I built my 34' steel sailboat I invested in a Milwaukee heavy duty nibbler. (3/16 capacity) It was expensive, but did an excellent job of plate cutting using a batten clamped in place as a guide with very little fit up required after cutting. After I finished with it (about 6 years later!) I sold it for about 70 percent of cost. I'm a great believer in buying good tools, using them for good results, then selling when finished. It's cheaper than renting and the results are worth it.
Doug
ps. I resolved the fuel tank problem. Ended up finding a new poly tank that did the job about $250 to $300 cheaper than metal.