hello!
when doing repairs, or hotcoats, i have trouble applying a minimal coat
i use a brush and push hard
but this layer i get is too thick to my liking [too heavy]
is there any other, better way to apply less resin?
thanks
[quote="$1"]
hello!
when doing repairs, or hotcoats, i have trouble applying a minimal coat
i use a brush and push hard
but this layer i get is too thick to my liking [too heavy]
is there any other, better way to apply less resin?
thanks
[/quote]
I'm no expert, so take this with a grain of salt. But in certain situations I have used a small foam roller to apply a thin coat of epoxy resin (generally referred to as a weenie roller), with good results.
Thanks for the idea Huckleberry, and thanks for the question Wouter. I've had the same issues and have searched the archives looking for answers and had no real luck. I've tried heating the resin to thin it, but then it starts to cure more quickly and becomes harder to spread. Would like to try Resin Research's Additive F, but that's not readily available in Oz. I've considered other thinners (wax in styrene, xylene, denatured alcohol, etc), but from what I've read sounds like the cons may be worse than the pros. But then again I have no first hand experience in using any of these. Any other ideas are most welcome.
I've done the heating (to speed up curing) and dna (for thinning) also, additive F is good, but not a thinner. I didn't have any problems with thinning a bit with denatured alcohol, but I know its not recommended by some, and I've only done it on small areas, not a whole board.
I tried the roller after reading on internet of a guy who finishes beautiful wood canoes with it, and I build wood boards mainly.
http://www.laughingloon.com/epoxy.html
I also encountered an article online about painting your car with a roller
http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=2331682&page=0&fpart=1&vc=1
- so I gave it a try and actually painted my work truck with a foam roller! I received a lot of ridicule from my friends and wife, but found that a foam roller in the right hands can lay down a thin coat and give a nice finish. When thin matters, it works for me.
I stopped useing brushes on epoxy resin a couple years ago and seldom use a squege. I buy 9 inch Poly rollers (black) or West systems poly rollers (Yellow). and cut them to length depending how big a job any where from 1 in to 3 inch. I put the mixed resin into a shallow pan. Dip the roller into the pan and then slowly roll the resin onto the glass cloth. Don't put the resin on thick or try to force it into the cloth. Just let the cloth wick in the resin. Because you are putting the resin on so thin bubbles are not a problem. It is tempting and easy to put on to much resin and then bubbles become an issue. White cloth spots mean not enough resin . Shiney spots to much resin.. If you get shiners you have to pull the resin off with a squege.What ever you pull off with a squege is waste , don't even try to use it or you will really have bubbles. After wet out I do a fast pass with a heat gun. For fill coats same method , use a roller. Always think thin. If the roller slides and slips your useing to much resin.If it feels like it is sticking then not enough resin. Better not enough than to much, you can allways put more. I do three fill coats.It is best if all the coats are done back to back. As soon as one coat is set enough to touch then it is ready for another coat. When I have a big job to do I will nap for a couple hours between coats and then do the next coat. I like to do it all in one sesion regardless of how long it takes. Pisses my wife off cause I may be in the shop for 24 or 48 hours. For a small boat those long sessions can save dozens of hours of sanding an cleaning. One long sesion and you don't need to do any sanding untill its time to shoot paint and if you did a good job, Sand with 150 and shoot paint , varnish ,whatever ! It's worth your time to make up some one foot squar panels to practice on. After a half dozen panels you should have it figured out. It I were at my home computer I would put a link up to the Kayak sight where I learned this, If I remember when I get home to night I'll post a link.
Darn Huck !! You posted your reply while I was typeing my post .! Your truck looks good ! How did you prep it before painting ?
thanks ogre, just prepped like you would any vehicle paint job: pulled out the dents, sanded and filled the minor dings, wetsanded everything, removed all the easily removable trim, and masked off
nice, detailed post, I'll have to re-read until I've got it down
brush with thinned epoxy (additive F really helps) was not thin enough? If so, just spray acrylic. Forget the epoxy, as you prolly won’t get enough strength out of it anyway.
Well dog my cats, I did not know additive F was a thinner. Honestly.
Huck since you tried it, what about using the roller method with the H2O Clear coat stuff posted up a while back?
Technically, I don’t think F reduces the viscosity, but does help it flow better. And sand better. Crisps it up a bit so it is easier to sand.
Huck your a maniac!
Yes. I have been told that.
[quote="$1"]
Huck since you tried it, what about using the roller method with the H2O Clear coat stuff posted up a while back?
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Man, it would be worth a try. I've been itching to get some of that stuff and give it a go - thanks for reminding me about it!
howdy ogre,
not sure if i got it right, maybe you can clarify your “back to back” method above, say :
-
lay down fiberglass cloth on HWS deck
-
apply resin on cloth on deck with a roller until fully wetted out right to the taped-off rails
-
siesta nap until first coat is touch-dry . . .
at this point, do you already cut off the resin-hardened fiberglass cloth along the tape edge with a blade cutter, sand the edges until feathered, and then do the other side of the board?
or apply all 3 coats on the same deck, nap in between, cut off the excess cloth along your taped edge, sand until feathered, and then do the other side?
carper’s glassing 101 video doesn’t show everything a first-time glasser needs to know before he messes up, that’s why i’m asking you instead! hehe
cheers,
For ding repairs, I wet the area with resin, then put the patch on, rather than put the patch one, then try to wet it out and pull out excess… which can cause the patch to move. Just wet the prepped area with resin using a gloved finger, and set the patch on. I’ve done multiple layers like this successfully.
For “fill” coats, or basting a lap or fin box patch edge, I’ll use a spreader. The hard edge lets me put a very specific amount of resin only where I want it.
For hotcoats I mix just enough, and paint it on. I’m usually just making it to get complete coverage, with very few drips. Warm resin, Add F, and NO THINNERS. I press the brush down hard, and use it like a squeegee, at an angle, with the bristles all bent over at the base. A firm hand moves the resin around evenly, and does not leave a overly thick coat of material.
Wouter,
You are having a tough time getting a thin coat of epoxy on your hot coats?
For what it's worth. Here's what I do to get a super thin hoat coat.
1) Heat the epoxy only side of the mix to 75+ degrees
2) Make sure my room is 65 degrees no more. This allows any excess epoxy to run off the board over time.
3) Pour the epoxy out in long lines tip to tail on the board
4) (Here the big tip) Don't use a brush, use a bondo spreader to spread the epoxy. Pull it around like you are doing a lamination
5) Now tip it out with a disposable brush
The spreader will get the resin around, but not fill any air pins. The brush will fill the air pins and make a nice bubble free hot coat.
The warm resin will flow around like poly resin, but the cool air and thin coat will slow the therm reaction so the resin will take some time to kick. letting it take a little more time to kick will allow any resin to slightly drain and drip off. Usually this technique will be very minimal on epoxy. ie, I used 6 oz of some off brand epoxy to hot coat a 7'7" yesterday, I probably could have gotten away with 4 oz. I had a pretty good amount of epoxy on the floor using this technique.
Ok so I just ran out to the shop and snapped this picture of the epoxy hot coat using the method above. See how it just barely fills the weave. Just enough to fill any air pins. And hopefully a light hand on the sander too!
I see nearly ALL the laminators doing epoxy hotcoats like they are polyester, dammed up tails become sooooooooooo thick that it takes too much work to bring them back to where they should be.
I apply an epoxy hotcoat like I would be painting a house, wet my brush and apply, re-wet, do again, tis way you are only using enough to cover that area and not flood the board.
I did one board and tried to scrimp on the resin, barely had enough to cover the deck, but when it came to sand, a sheet of #220 was all it took to remove the shine and NOT have to burn through a quart of resin. The glass is where the strength is, not a lake full of resin
[quote="$1"]
I see nearly ALL the laminators doing epoxy hotcoats like they are polyester, dammed up tails become sooooooooooo thick that it takes too much work to bring them back to where they should be.
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Funny you mention that, I had just done one such hot coat when I read your post. I like to make the tape "dam" to get a nice, hard edge on the tail. However, the way I load up the resin in the dam, I'd hate me if I were the sander (I am the sander so I guess I should hate myself???).