Malahini Progress

billy c · **Posted:** Wed Jul 21, 2010 11:04 am

remove the other ones and once you have finished breaking/removing them, tap the batten off. that should leave the steel screw sitting proud of the frame... take your vice grips and have at it!
-Billy

Iggy · **Posted:** Wed Jul 21, 2010 11:54 am

Ouch.. ya.. I've had that happen to me also.

For 'temporary' screws I use a fatter head, thinner shaft and shorter screw than what I use in the final fastening.

White oak might be hard to 'pop' out of the battens.. particularly if you are using 2 screws per batten/frame. I only used 1 screw per batten/frame.

I'd probably try to use a hammer & block and try to tap it off first to see how much effort/damage it might do.

If that fails, I would probably drill beside the screw in a few spots and try it again.

I wonder if wetting the material with hot water would help soften it for pulling off.. or would that make it swell and harder to remove?

Onplane · **Posted:** Thu Jul 22, 2010 3:14 pm

Ok, so even with laminations on the sheer, one broke...

2nd lamination (outer) on the right side. Hairline crack about halfway in, about 2 inches long down the middle. Looks like it cracked through the bottom, but not the top, guessing it is cracked at an angle of some sort, but it is epoxied and clamped in place & cured.

So, the question is, what do I do now? Leave it? Cut out the cracked section and then epoxy back in place? try to squeeze epoxy back into the crack and clamp? Not much room to work in, but maybe a syringe could get it in there...

As is I hardly saw the crack, until further inspection, because the sheer is still bent correctly and looks fine minus the crack.

Trackhappy · **Posted:** Thu Jul 22, 2010 3:53 pm

Onplane wrote:

Ok, so even with laminations on the sheer, one broke...

2nd lamination (outer) on the right side. Hairline crack about halfway in, about 2 inches long down the middle. Looks like it cracked through the bottom, but not the top, guessing it is cracked at an angle of some sort, but it is epoxied and clamped in place & cured.

So, the question is, what do I do now? Leave it? Cut out the cracked section and then epoxy back in place? try to squeeze epoxy back into the crack and clamp? Not much room to work in, but maybe a syringe could get it in there...

As is I hardly saw the crack, until further inspection, because the sheer is still bent correctly and looks fine minus the crack.

In the model plane world, we use Super Glue, or "CA". You can buy a thin version that will wick into any crack, no matter how small. Be careful, it is nasty stuff that is hard to see, runs everywhere and burns your fingers. However, it does get in there and basically turns the wood solid. If that bit is in place and the right shape, I would get some thin CA from a model shop and fill the crack with it. It sets solid and many model planes fly with only that holding it all together. Encapsulate as per normal.

Onplane · **Posted:** Fri Jul 23, 2010 4:36 am

So, I got back in from dinner last night and the sheer crack had gotten a little worse. So I decided to try and fix it.

Mixed up some non-thickened epoxy, and forced it into the joint. Then wrapped it with wax paper, like a bandage, then applied some clamps to the effected area. Hope it cures okay... Couldn't stand to let it sit as is anymore...

Onplane · **Posted:** Fri Jul 23, 2010 4:40 am

Some sketches of crack in sheer...

Iggy · **Posted:** Fri Jul 23, 2010 6:59 am

I had that kind of fracture like that as well, but in my forward batten. I was able to get some epoxy underneath it, wrap in wax paper with a 'splint' on the outside (flexible 1/4" spruce board) that I clamped tight against it till everything cured.

It its the right shape and holds in place after curing, I wouldn't sweat it too much.

Onplane · **Posted:** Fri Jul 23, 2010 7:57 am

When the first lamination of the sheer was put in place, it was steamed to conform to the bend. But the 2nd lamination was not steamed, because it bent into position fairly well. Read: No creaking, cracking, or obvious issues... (Both 2nd laminations on the sheers and chines were not steamed, whereas the 1st were)

Now that I have epoxied the crack (and since the 2nd (outer) lamination has been epoxied to the 1st) should I go back over both laminations with the boiling water and towels to steam? Would this relieve the tension in the outer lamination?

With both laminations epoxied to each other, it shouldn't modify the curve... Just don't want to get into another crack situation later on down the road when I put the planking on...

Iggy · **Posted:** Fri Jul 23, 2010 8:28 am

I am betting that particular problem was just part of the normal flaws that can appear when using a natural wood product. I am sure you chose the best material/grain you could, but there are just some things we cannot pick up with our eyes and don't 'surface' till a while later, after you put some stress on it.

I am not sure re-steaming/boiling water on the outer sheer will do much other than add more time to the project. With the laminations I would bet that IF anything else develops it will be out the outside edge.. and by the time you are done fairing the material and applying the outside plywood everything will be sandwiched together and make a very strong composite structural unit, stronger than the sum of its parts.

In other words.. don't overthink this.. from what I've read and my limited experience its very 'normal' to have something like this happen from time to time during the build. You're doing the right process and taking the right precautions.. and that will minimize the issues but not eliminate them. Its hard to anticipate these sorts of issues.. and in almost every case there is always a way to correct problems if they do happen.. like you did with the outter shear just now.

Onplane · **Posted:** Fri Jul 23, 2010 9:35 am

Thanks for the encouragement Iggy...

I was thinking the outside sheer gets faired down in that section pretty well anyway, and that would reduce stress as well.

I will take another look at it tonight after it cures and hopefully everything will hold together until I fair, which should be soon.

Iggy · **Posted:** Fri Jul 23, 2010 10:55 am

Like you said, when you fair the outter sheer you are definately going to remove a portion of the area that got fractured anyway.

There is definately a 'faith factor' when building a boat.. having to trust that that tiny little 1 1/4" square section of wood will hold the stresses of the plywood and deck loads and trailiering back and forth. The beauty of the design is that it just gets stronger as you move along.. support becames more evenly distributed.

But I sure remember holding my breath when fairing down the chine and sheers.. wondering what might happen when I screw a bunch of holes in it an put a bunch of pressure via clamps to pull the plywood down to fasten them together.

I also remember being quite tentative to even start the fairing process myself.. I dragged my feet at least a few evenings till I got my confidence up.

Now that my bottom hull plywood is fully installed.. I don't hold my breath quite as much.. and I don't drag my feet near as much

Not saying you are doing that.. just saying its natural... at least it was for me anyway

ttownshaw · **Posted:** Fri Jul 23, 2010 12:31 pm

Sorry Onplane, I've been super busy and haven't been able to post pics for you yet.

I had a similar issue on one of my spray rails although the sheers might be a little too narrow to try this but it's still worth some consideration. The crack in my spray rail was identical to what you described on your sheer. I cut the area out and laminated in two strips of white oak. First I made a couple of relief cuts parallel to the vertical split about 6" each side of the crack to keep it from spreading while doing cutting it out. I used a circular saw set to the depth of the crack and made multiple passes to notch out the area. Then used a chisle to clean it up. Glued/screwed in the strips of oak. Then sanded everything smooth. The results were great. Here's a pic before sanding back to fair:

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ttownshaw · **Posted:** Fri Jul 23, 2010 12:38 pm

Oh, and one thing I really liked about this solution is that it resolved a grain runout problem. I put the strips in at opposing grain directions so that it would tie everything together nicely.

Onplane · **Posted:** Tue Jul 27, 2010 8:29 pm

Making more progress...

Solved batten screw issue (Major PIA... over half the screws sheared... but I was able to salvage the battens)

And I fixed the crack (Re-epoxied and held secure)

I also had a fairing issue where the sheer clamps were set too far into the frames, so I had to add another filler shim.

But after all these issues, I am finally starting to put the sides on. (And might I say, wow! what a bend at the transom side plywood! - Kinda afraid to let the strap loose!)

Epoxied up the right back side, ready for the left back side, and then on to the front side pieces...

I plan on doing a butt joint with my Meranti ply, and I am thinking over the butt block, which I believe I will use scrap 1/4" ply (same as side ply) overlapped 4 inches on each side. I can get clamps on the butt of the back piece, but how to you clamp up the other side after the front piece goes on? I really don't want to put more screw holes in the ply that I will have to fill in later... but if I have to I guess I have to. Any ideas?

Thanks,
Charles

ttownshaw · **Posted:** Tue Jul 27, 2010 8:36 pm

Yep, I see you've got the same disease us other boatbuilders have...clamp-itis. Looks good Onplane! For the front part of the butt joint...if you are real careful you can screw from the inside until the epoxy sets up. If a screw just slightly pokes through don't worry, some epoxy thickened with wood flour can hide it. I remember that bend at the transom vividly! I didn't stop worrying about it until after the glass was on and the boat was flipped. It will hold...don't worry too much!

Glen-L.com

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