How much epoxy?

I don't know how much it will take for sure but I'd start with a 1 gallon kit of no blush from Raka and see how far that gets you.

The exterior will take more. After wetting out the cloth it will probably need another 3 coats to fill the weave deep enough to sand.

The interior will only take the amount to wetout the cloth, assuming you're not going to fill the weave on the inside.

Record how much it takes to wet out the exterior and make sure you have enough when you start on the interior. Would hate to run out 3/4 of the way through wetting out the cloth.

Alan

Thanks Alan. Do you prefer their thin, medium, or thick resin?

Bob

Cheeseandbeans said:

Thanks Alan. Do you prefer their thin, medium, or thick resin?

Bob

Click to expand...

The thinner the better. Their 127 resin is all I've ever used from them.

Alan

They sell a 6 quart kit, which is what I would suggest. There's nothing wrong with having a little too much epoxy, compared with too little. Agreed on the thinner epoxy, and I would go with the non-blush slow hardener.

Mark

dogbrain said:

They sell a 6 quart kit, which is what I would suggest.

Click to expand...

Yes, that's what I meant too. When I said 'gallon kit' I was thinking gallon of resin+hardener

Alan

I agree with above posts.
RAKA 127 resin, and 350 Non blush hardener.
If there is any chance you'd build another canoe ?
I'd go with the three gallon kit.

I would go with the 6 oz cloth. Same price, but a bit more durable, unless you are going with 4 oz S-glass.

Jim

Plus one on all of the above although I don't think Raka sells s-glass. IIRC, I went to US Composites for that.

Not that I'd recommend doing as I do but... The 3 gallon kit (2 resin, 1 hardener) is almost enough for 2 boats... Probably best to get 6 gallons and do 3.

Thank you all, much appreciated.

Jim- sadly I don’t think I will build another strip canoe. I didn’t enjoy the construction process. Being my first strip canoe, I am sure the next one would go smoother, but I prefer other construction methods.

That said, all of the “how to” posts from the builders here were a great help and I am pleased with the results so far.

Bob

Was going to chime in that it will likely be on the low side of 1.5 gallons (US) of mixed epoxy. I am just setting up for my next build and being lighter is always a consideration for me.

When you wet out the glass on the boat you have to watch for starved areas where the wood below sucks up more epoxy and you have to add more to keep the glass wetted fully, until it is time to squeegee all the excess off. However in those areas you have extra epoxy pulled in by the wood ( and the extra weight that is there to stay).

This build, I am planning on trying a fill coat to limit extra epoxy going into the hull .... I usually argue against the fill coat as extra work, based largely on the requirements of the commonly used 5:1 epoxies, limiting re-coat times without sanding.

However, the System 3 Epoxy got my eye, after reading the epoxy blog post over on the Laughing Loon site ... with a 72 hour re-coat, with no sanding and full chemical bond ... well, that just changes the whole epoxy application paradigm IMO. Thin seal coat today, later today put on the glass and initial coat or wait till tomorrow ... just eases that application schedule so much.

It costs a little more, but there are clear cut advantages that I think are worth paying for in this case. I would at least take a read and add that to the items helping you make the decision.




Brian

Cruiser said:

However, the System 3 Epoxy got my eye, after reading the epoxy blog post over on the Laughing Loon site ... with a 72 hour re-coat, with no sanding and full chemical bond ... well, that just changes the whole epoxy application paradigm IMO. Thin seal coat today, later today put on the glass and initial coat or wait till tomorrow ... just eases that application schedule so much.

Epoxy, Fiberglass Cloth and Transparent Lay-ups on Strippers

Brian

Click to expand...

I've always wondered how people interpret that 72 hour thing ?
What would be the difference, if I waited 73 hours ?

A System Three Tech, told me it was better not to wait. Stating I would get a clearer, and better bond.

I have abided by that and had no issues.



Jim

Jim Dodd said:

I've always wondered how people interpret that 72 hour thing ?
What would be the difference, if I waited 73 hours ?

A System Three Tech, told me it was better not to wait. Stating I would get a clearer, and better bond.

I have abided by that and had no issues.



Jim

Click to expand...

Now you are just teasing us Jim ... any time frame on that " better not to wait"?

I don't plan on waiting the 72 hours to recoat, but moving from the ~3 hours recoat with most epoxies, to one that easily allows projects to sit overnight, that alone changes the entire epoxy application scenario.

Did your tech give some indication of "time" for the clearer, better bond ect.?


Brian

Cruiser said:

Now you are just teasing us Jim ... any time frame on that " better not to wait"?

I don't plan on waiting the 72 hours to recoat, but moving from the ~3 hours recoat with most epoxies, to one that easily allows projects to sit overnight, that alone changes the entire epoxy application scenario.

Did your tech give some indication of "time" for the clearer, better bond ect.?


Brian

Click to expand...

Waiting to 72 hrs, just increases the likely hold of contaminates, and blush.
Blush is the result of moisture, ( Humidity ) and carbon dioxide reacting as the resin cures. The longer you wait after epoxy application, increases the creation of Amine blush.

So here is what I do and what the tech advised me.
If you are going the Seal coat route. It by the way has it's pros and cons.
Surface ready for the Seal coat, should be as dust free as possible, if not ? Dust particle will be high spots on the surface of the epoxy, lifting the cloth away from the surface. Yeah the down fall of seal coat.
Apply Seal coat. Test for high spots from dust, once the epoxy has lost Tack. If you have removed high spots by Scraping, not sanding because of dust.
Now apply cloth and wet it out.
I let the Wet out coat cure, to the stage that the cloth will not move, while I add Fill coats. Usually 4 to 6 hrs.
I then apply Fill coats at about an hour apart. The main thing with Fill coats, is to apply while the previous coat is still Tacky.
The big advantage of the Tackiness, is it will help reduce runs.

I used to use a Squeege, but have switched to Foam rollers. I get a more even application, and no lines from the Squeege.

I started Seal coating my hulls, but have learned the hard way to skip it. If you do a good job of filling staple holes, cracks and voids ? No need to seal coat.

So epoxy and fresh fruit have a lot in common. It's better when they are both Fresh .

Jim

Not to further derail the thread but, out of curiosity, I just called Mike @ RAKA (same guy always answers the phone- extremely helpful & knowledgeable). He tells me that in a 65 degree (F) shop, 8-12 hours between coats would not cause any issues at all. Says you COULD extend it a bit even but he wouldn't.

Overnight wouldn't be an issue at this time of year with theirs if anyone chooses to use them.

It would be the best, if we could, in one application, lay the cloth, wet it out and fill coats at one time. No need to worry about blush between coats.

With my method, I'm up late and usually get up sometime during the night to apply that last fill coat.
I know others wait until the next day.
That is fine !

As I stated applying fill coats while the previous coat is still tacky really reduces runs.
I've scraped enough runs in my day, and preventing it, is why I'll get up in the early AM to apply.
It's worked for me. No problems with blush.
My 2 cents worth.

Jim

Gamma, I agree the epoxy setup would be delayed with temp, I will assume at those times you are specifying a slow hardener.

Jim ... when I glass, I clean the shop and and prep the canoe ... TBH I cannot even imagine missing enough dust to actually lift the cloth, any bits left on the surface will likely disappear into the cloth being laid over it. Once I read the LL blog I knew I was going to try the System 3 epoxy for this build, the re-coat timing just makes that easier.
The idea/decision of using a seal coat was actually resulted from your comments on using S glass on your last build and not achieving any weight savings ( I paraphrase). Since I am going that route on this build, I did a pretty indepth analysis of what to expect from the S glass layup.
I expect two things to result from doing the seal coat:
1) a thinner epoxy coat resulting in less actual epoxy being used to seal the wood surface (and less weight), than would be the case by applying the glass directly. Since the substrate will be sealed, I expect to use less epoxy on the glass itself, reducing squeegee waste.
2) I have noted a couple of forum posts that indicate that sometimes folks get wet out lines .... I have had those and it's usually when you can't get to that area fast enough while doing an all-in-one application. I figure the seal coat will go on fast enough to eliminate any chance of wet out lines and so result in a more uniform colour.

Blush should be a non issue as there are so many "Blush Free" options on the market these days, the System 3s I am going to use, I believe you are using a Blush Free RAKA, MAS has options ... so I think a little planning should pretty much eliminate that worry ... I will however likely continue to wash the hull once cured, lol.


Brian

Good ! Not all builders, especially Newbies, keep a dust free enviroment. And Yes, any irregularities left between the hull and the cloth, will raise the cloth. I've scraped and repaired enough of them.

Seal coats are fine, it's just a little extra work. I know you won't have any problems ! Keep us informed as to your weight savings !
It's tough making them light and strong, at the same time, without spending extra money!

System Three's Clear Coat is a great epoxy ! Especially for wet out. It is how ever, too thin for fill coats.
My first boats were built with Clear Coat . Buying it in 15 gallon kits, it was actually cheaper than varnish, at that time. That changed with new ownership.

Squeegee lines really irritated me. They occurred during wetout for me. I always hoped they would fade with fill coats. I could still see them. Time, several years, seems to have faded them.
The first foam rollers I used, were from System Three. They were black, and I ordered a dozen for each hull I built. They worked good, but soaked up a lot of resin.
Those little white "Cigar" type are my favorite now.

I never washed my hulls. Sanding removed the blush, and I haven't had any problems with RAKA's epoxy.

Sorry to the original poster ! I can get off topic easily, especially this time of year !

Actually, MAS is a very clear epoxy, just seemed a little harder than RAKA.
I think you will be fine, with either one!

Jim