Bob Smith Finish Cure on wood boats

[emspjay]

So I built many airplanes from wood but not any boats before. I have a Dumas Bug Swamp buggy to build and was thinking of also doing a big outrigger from wood at some point. So for now I purchased one of the little 15 inch Dumas 41' USCG Utility Boats and have been working on it to practice my building skills on. I got the basic main hull done and put in the electronics from a cheap FT007 boat from Ebay. I did seal the whole inside with 15min Bob Smith Epoxy. I have a lot more outside work and sanding to do so my main question is when that is done should I coat the whole outside with Bob Smith Finish Cure? Or is there something you guys recommend that is better? I attached a couple photos of my project. And a link https://www.amazon.com/Finish-cure-20min-epoxy-Bob-Smith/dp/B001NI8MP8

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[785boats]

I use an epoxy fiberglass finishing resin on all my builds. Inside & out. Thinned down by 30% for the first coat so that it soaks into the wood, second coat is just thinned down by about 20%.

That epoxy you used is a glue, not a fiberglass resin.

[emspjay]

I use an epoxy fiberglass finishing resin on all my builds. Inside & out. Thinned down by 30% for the first coat so that it soaks into the wood, second coat is just thinned down by about 20%.

That epoxy you used is a glue, not a fiberglass resin.

So what is your brand of choice for resin?

[meangenesracing]

West systems is the best. You can get it on ebay

[NativePaul]

I am unfamiliar with that boat, what wood is being used, and what do you want from the finish?

Epoxy laminating or finishing resin is what you need to use, west systems is a popular brand but they all do the same thing with minor differences between brands, so just buy whatever brand is available in your area.

As above epoxy can be thinned with IPA, and heat will also thin epoxy, if you want the best penetration stand both parts in a bowl of hot water before mixing. When thinned it soaks into the wood better for a more ding proof finish, or unthinned it can be mixed with glass microballoons to a thicker paste so it doesn't soak in for a less ding proof but lighter finish. The bond lines in ply will stop halt the absorption of epoxy so only the outer ply will be soaked, but thin resin will soak right through balsa and give it a lot of extra strength but at the cost of a lot of extra weight. Heat shortens the cure time of epoxy, and over thinning with IPA can result in microbubbles formed when it evaporates and porosity.

For the ultimate in ding proof finishes, apply a coat of thinned resin, let fully cure, sand, laminate a layer of 25gsm glass cloth on wit unthinned resin, let cure till tackyness stops, apply another layer of resin, let fully cure, and sand most of the last layer back off.

[Panchothedog]

What is IPA and can it be used to thin epoxy resin? If not 785boats !mentions that he thins his by 30% but what is he thinning it with? Thanks in advance for any information, most of my boats are glass but I am trying to revive a couple of old brushed motor wood riggers I built 20+ years ago and they need some help.

[emspjay]

Thanks guys! Lots of informative info!! I have a West Marine around the corner from me to get West Systems. I am guessing IPA that you use for thinning is Isopropyl Alcohol? This little boat is mostly all thin hobby style plywood, for this boat I just want to make it waterproof before I paint it. Now when I build the Dumas big swamp buggy I am going to use fiberglass cloth to add strength. And if I do a rigger in the future I will use cloth on that also for more strength.

[785boats]

So what is your brand of choice for resin?

The finishing resin I use, is sold by CG Composites. Mainly because they are just down the road from where I live.
Like NativePaul said, nearly all distributors have products that are very similar to each other. Probably supplied by the same manufacturer.

For thinning I use Methylated Spirits.

[longballlumber]

If you plan on building more than one wood boat, I too would suggest the West Systems 105 epoxy system. They have several different hardeners to chose from. They also have several different fillers also. Everything is compatible with each other. For some reason, I can't get to their website to link it.

105 - is the epoxy resin
205, 206, 207 - are all different hardener types https://www.westmarine.com/resins-fillers-fiberglass
They also have fillers - https://www.westmarine.com/search?Ntt=west+system+filler

good luck