epoxy inside wood hydros

[bilbis50]

Could one use regular polyester resin instead of WEST SYSTEM EPOXY on the interior of a 1/8 scale wood hydro for waterproofing? Billy

[Doby]

Yes.

[HTVboats]

Polyester resin is porous and water will wick thru it. Gelcoat is what seals a boat. If you made a bucket out of plain resin it would leak water. Not fast enough you could see it as it would evaporate on the outside surface. enough to soak wood over a period of time. Use epoxy or clear gel coat. Ask anyone who repairs fiberglass boats.
Mic

[longballlumber]

Still Epoxy, but I have used this product also. It's much thinner so you will need multiple coats to get it completely sealed

https://www.systemthree.com/products/clear-coat-low-viscosity-epoxy-sealer

What West Systems product do you have or are you referencing to?

[MadProps]

epoxy is the sophisticated big brother to fiberglass resin

Epoxy is known for its higher bonding capabilities overall. An epoxy’s relative strength can hold up to 2,000 lbs. per square inch, while a polyester resin can hold less than 500 lbs. per square inch.
Epoxy is more resistant to wearing, cracking and peeling, and corrosion or damage from chemical or environmental degradation. Polyester is more fragile and useful for temporary fixes, or low-stress use.

important rule of thumb...... epoxy over resin but no resin over epoxy

[JohnZ]

What I like about West Systems is that it is thin enough to wick into wood joints much better than ordinary hobby epoxies. After all West Systems is all about boat building and repairing. Van Dam Boat Works in Boyne City , Mi. builds beautiful custom boats using West Systems.
Besides, they're good guys to talk to. You can call them on the phone , (avoid lunch hour), and get answers.

[Dr. Jet]

When I was building and repairing fiberglass sailplanes, I discovered what I consider the finest epoxy ever. MGS L-285. The drawbacks are it's only available in gallon quantities, and the catalyst (either "2 hour" or "5 hour") is an additional cost. I put the hour rating in quotes as that is the pot life, not the cure time. The 2 hour stuff takes a good 24 hours to cook off. The 5 hour stuff takes two days. It has the consistency of maple syrup when initially mixed and will flow into every nook and cranny within a few hours.

It's expensive, (a gallon plus catalyst will set you back $150 or more), but if you build a lot of composite parts, nothing compares to it. Most composite aircraft specify this epoxy only. The mix ratio is precise: 100 to 40 by weight.

It is available at Aircraft Spruce, and they too are very helpful and a pleasure with whom to do business.

P.S. I'm going to build a 1/20 1980 Atlas Van Lines and this epoxy will coat the entire inside and be widely used in structural portions of the build. I also use this epoxy mixed with Cab-O-Sil for building up ride surfaces in vacuum-formed or crappy molded hulls.

[JohnZ]

That stuff is expensive and unless one is going to do a lot of building or has the cash to spend, personally I would opt for something like System 3 or West Systems. A lot less expensive and I doubt anyone would notice the difference.
Still, it must be an excellent adhesive... must be certified for aircraft. I know that Aircraft Spruce sells all three products.

[tedric]

epoxy is the sophisticated big brother to fiberglass resin

Epoxy is known for its higher bonding capabilities overall. An epoxy’s relative strength can hold up to 2,000 lbs. per square inch, while a polyester resin can hold less than 500 lbs. per square inch.
Epoxy is more resistant to wearing, cracking and peeling, and corrosion or damage from chemical or environmental degradation. Polyester is more fragile and useful for temporary fixes, or low-stress use.

important rule of thumb...... epoxy over resin but no resin over epoxy

Good insight. I'll be repairing and sealing my boat project right after we finished installing the h&s performance tuner and new exhausts system on the current truck project. Epoxy seems the best choice.