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Re: modified malahini

Posted: Tue Jul 18, 2017 11:34 am
by Bill Edmundson
Bryan

If you are going to glass the hull, I don't think wetting is that important. I would do it if I was going varnish only.

Bill

Re: modified malahini

Posted: Tue Jul 18, 2017 12:52 pm
by DrBryanJ
I'm not glassing the hull, only stain then epoxy and varnish (or clear coat).

Re: modified malahini

Posted: Tue Jul 18, 2017 1:06 pm
by Denon Osterman
Hey Bryan, that's a very cool build you've got going on! I'm not sure how I missed the post earlier but definitely a good idea to go with an existing hull bottom...when I modified the plans for my rampage just to change the sheer line, it ended up being a huge headache to get everything to work out!

All of that being said, what stain are you planning to use? A lot of stains will prevent epoxy from working at all, unless you use something like CPES (which is nasty stuff IMHO). This link has more info on what does, and does not work...I went with Minwax because it's by far the most common in my area, and ended up having to CPES the whole thing. The adhesion still isn't ideal and I'm a little worried that 10 years down the road I'll have to re do the entire bottom :shock:

http://epoxyworks.com/index.php/epoxy-a ... er-stains/

That being said, I've never heard of any issues with varnish over epoxy...and when I used epifanes varnish I didn't have any issues with adhesion there at all (just with the stain). But, Roberta likely knows more than I, so I'd be curious to hear more too!

Re: modified malahini

Posted: Tue Jul 18, 2017 1:35 pm
by DrBryanJ
I am planning on using General Finishes stain. Carl of "Building the Vera Cruise" used it on his transom without epoxy adhesion problems. I'll do a test panel before applying any to the boat just to be sure. (I want to check the color anyway)

Bryan

Re: modified malahini

Posted: Tue Jul 18, 2017 2:01 pm
by WayWard
I'm still in the learning phase

I'm curious about the choice of forgoing the fiberglass. I've built a couple stitch and glue kayaks and when the weave is filled the glass is virtually invisible.

Mind if I ask what motivated that decision?

Re: modified malahini

Posted: Wed Jul 19, 2017 3:30 am
by DrBryanJ
WayWard wrote:I'm curious about the choice of forgoing the fiberglass. I've built a couple stitch and glue kayaks and when the weave is filled the glass is virtually invisible.

Mind if I ask what motivated that decision?


1: Still concerned the weave might show some.
2: Worried about my ability to fiberglass
3: Fiberglass doesn't add strength, only abrasion resistance, so I will fiberglass to waterline.

Re: Sanding Hell!

Posted: Wed Jul 19, 2017 5:37 pm
by ToddM
DrBryanJ wrote: Questions: should I wet the wood to raise the grain and sand one more time?
What is the best way to clean the dust off before staining?
Bryan

I would only purposefully raise the grain if I planned on using a water based finish. In my experience, oil based and solvent based finishes do not raise the grain, therefore it is not necessary to raise the grain first and sand it smooth. I have no experience with using epoxy to seal first and as such, have no idea if epoxy will raise grain.

Most folks will say a tack cloth is best to clean dust. I don't particularly like using a tack cloth, so I end up using a slightly water moistened cloth towel.

Re: Sanding Hell!

Posted: Wed Jul 19, 2017 5:39 pm
by WayWard
ToddM wrote:
DrBryanJ wrote: Questions: should I wet the wood to raise the grain and sand one more time?
What is the best way to clean the dust off before staining?
Bryan

I would only purposefully raise the grain if I planned on using a water based finish. In my experience, oil based and solvent based finishes do not raise the grain, therefore it is not necessary to raise the grain first and sand it smooth. I have no experience with using epoxy to seal first and as such, have no idea if epoxy will raise grain.

Most folks will say a tack cloth is best to clean dust. I don't particularly like using a tack cloth, so I end up using a slightly water moistened cloth towel.



I've heard that tack cloths can leave a chemical residue that can interfere with a varnish curing.

Re: Sanding Hell!

Posted: Wed Jul 19, 2017 8:08 pm
by ToddM
WayWard wrote:
I've heard that tack cloths can leave a chemical residue that can interfere with a varnish curing.


From what I can tell, they are usually cheesecloth with wax embedded. Does the wax stay on the cheesecloth? I dunno.

Re: modified malahini

Posted: Thu Jul 20, 2017 3:17 am
by DrBryanJ
You can make your own tack cloth with cheese cloth, turpentine and varnish, so I don't see how it could interfere with varnish curing. I think most water based finishes do not recommend using a tack cloth.

Re: modified malahini

Posted: Thu Jul 20, 2017 3:50 pm
by mrintense
DrBryanJ wrote:I am planning on using General Finishes stain. Carl of "Building the Vera Cruise" used it on his transom without epoxy adhesion problems. I'll do a test panel before applying any to the boat just to be sure. (I want to check the color anyway)

Bryan


Please make sure this is going to work for you. Although mine has held up fine for a few years and in the heat, I cannot say for certain it will hold up when it starts getting regular exposure to sunlight. On the other hand, whenever I open my garage to work on the boat (which is nearly everyday) the sun is beating down on the transom for the first half of the day. I keep it covered but it still gets plenty warm. No issues with adhesion so I am hopeful it will be okay.

One thing I did do was let the stain dry for a week if I recall correctly before applying the fiberglass. and BTW, on mine, I used a lighter weave cloth and it did go invisible, but I doubt it will look as nice as pure stain and varnish only. I am happy enough with it's appearance however.

Just reread this, sound wishy washy! :lol: :lol:

Re: modified malahini

Posted: Thu Jul 20, 2017 4:40 pm
by DrBryanJ
Carl: Doesn't sound wishy washy to me. I think we all have concerns about what we've done at some point in the build.

As I get closer to this phase of my build, I went back and reread the section of your build where you stained your transom. You have posted so much useful information. I really appreciate that.

Re: modified malahini

Posted: Thu Jul 20, 2017 6:39 pm
by JimmY
FYI... These tack cloths were recommended to me: "Surgical Blue Premium Tack Rags" https://www.amazon.com/gp/product/B001YJFYE8/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

They are supposed to be ok for water based finishes. I used them with System 3 WR-LPU paints with no problems. Your mileage may vary.

Re: modified malahini

Posted: Mon Aug 21, 2017 4:17 pm
by DrBryanJ
I have finally finished sanding :D (for now :( ).
IMG_0029[1].JPG
,
IMG_0030[1].JPG
. Started with 60 grit. Drew pencil marks over entire boat. With long board against grain did 45 degrees to right until pencil marks gone, then 45 degrees to left removing next set of pencil marks. Finally 60 grit with the grain removing another set of pencil marks. Left plywood at this stage and only worked on sapale boards on sides, bow, and transom. Again using pencil marks to be sure I did entire surface, used 80, 100, 120 and lastly 150 grit with the grain. I was going to stop at 120, but I am using General Finishes gel stain and they say to sand to 150, so 150 it is. This was a very long tiring process. I need to find a power assisted way of doing this instead of a manual long board. I have also rounded the edges to prepare for fiberglass.
IMG_0031[1].JPG
The saple holes are filled with Famowood mahogany wood filler. I hope they become less visible with the stain.

Re: modified malahini

Posted: Mon Aug 21, 2017 6:27 pm
by hoodman
Looks great. Even if the filled holes don't blend perfectly it will add to the character of the boat.