So West System Epoxy Resin Can Be Used As A Complete Substitute For Gelcoat ?

[albergsailor]

if someone can awnser this question i would really appreciate it. From what ive been reading it seems that the resin stuff 105 and the hardener can be a complete substitute for gelcoat. They dont state this in those words as much as they should it seems. My gelcoat is screwed, fiberglass laminate seems great. Cracks and voids in gelcoat all over from years ago when i sanded off all the blisters(bout size of fingernail, but all over the boat, it would take a TON of filler. Lucky me i just bought a 185cfm compressor and rigged a harberfreight blaster that works like a charm. I did watch the enlightening utube video about the west system. So from the looks of it i should go ahead and blast away the junk gelcoat with black beauty and replace it with the west resin?,along with the fairing compound, then mix in the barrier coat into it, then last of course antifoul. Please sumone confirm this lol.. Thanks!

[thinwater]

Epoxy resin cannot stand UV without a paint covering, gel coat can.

Unless you paint the epoxy, you will see damage within a season. Epoxy boats are generally painted with a 2-part polyurethane, such as Imron or Awlgrip.

[djmarchand]

If you are talking about below the waterline, many professional blister repairers don't gel coat after stripping the blistered gel coat and laminate. They just barrier coat it and bottom paint it.

David

[bruce smith]

Epoxy is superior to gelcoat in every way.But it is the base of a system , gelcoat is stand alone.
gelcoat being polyester resin with color and a bit of wax.
However, it is not an easy job to switch out.
Applying west is messy, it does not dry like paint, it drips and runs and makes amine blush and is 'spensive. And lets not forget labor intensive. Even needs a bit of skill.
If the boat is disced off by an expert, it will not need a ton of filler. The filler itself needs to be epoxy. do not mix up the different resins.
Assuming you are talking of underwater, but on a sailboat, except for the top coat ( anti foul or LP ) , the hull should be treated the same.
So , no short answers, this is only the beginning.

[albergsailor]

yes im talking about under the waterline. I appreciate the responses but seems i was misunderstood. My question was would it be a good idea to replace m gelcoat with west system epoxy resin . im talking about blasting off my entire gelcoat and substituting it with the west epoxy resin. Or wud doing so be too hard to Fare? or should i respray fresh gelcoat over the bare fiberglass, fare it, then proceed with the west system?

[Cheechako]

My vote is a big YES! then primer then bottom paint. must be done in a manner so all coats adhere to each other! If you do this and you just had those shallow small blisters, I doubt it will ever pop up again. If the remaining gel is dry, you dont really need to get it all off. The epoxy resing may go on a little Mottled, but no big deal. The vane blades in some jet engines are made mottled on purpose... maybe you'll be faster! Ha ha

[Ironhorse74]

Just a thought here. If you apply west systems to the thickness they specify for a barrier coat the cost is enormous. Interlux makes an epoxy barrier coat called 2000E. Way less money.

The cheap bastard.

[Cheechako]

Not as expensive as doing it again! Doesnt have to be West though. any good Epoxy resing (not paint). IMHO

[roverhi]

Sand blasting the gel coat is going to leave a pretty rough surface. To get it smooth again will probably take a several coats of thickened epoxy and sanding most of it off of every inch of your bottom. That's going to be a lot of unnecessary work.

Take any blisters down to good glass, fill back flush with epoxy and fiberglass fibers, maybe a layer of cloth or two if they are large, then grind flush. Sand the rest of the bottom down to bare gel coat and apply barrier coat. A stripper will make it a lot easier if there is a lot of bottom paint on the boat. Check with the yard before you do it, however. Same goes for sandblasting.

Epoxy resin is pretty much water proof so will seal the bottom like a barrier coat. Some people say you still should use an epoxy barrier coating designed for that purpose, however.

[Cheechako]

He's doing the blasting himself, so has some control. Blasting can leave anything from a smooth matte finish to a real shredded mess. It's all about pressure, media and nozzle size...right?

[s/v Jedi]

Another vote for Interlux Interprotect 2000E


Nick

[gulfstar37]

Our sailboat bottom was peeled and West put on about 15 years ago. No problems. I would give them a call. They are very willing to help and answer any questions you have. I am a little partial. Their factory is in town. However as mentioned on previous post there are many epoxies on the market. I have been very pleased with West service and willingness to help answer questions. I do believe they have a this process on their website.

[bruce smith]

gel coat, which is made of the same resin as the boat , at the same time, by spraying it in the mold first, is not an adhesive. Polyester gets hard, but does not actually stick.
So, adding gelcoat , or , re doing a gel coat , does not work.( Cept when it does)
Epoxy is an adhesive, and it is literally waterproof(cept when it isn't), so, retro fitting it works. A superior boat could be built if epoxy was put on the outside of a fg boat from new, but would be ridiculously expensive.
barrier coats ARE epoxy, formulated to paint on better than resin.
Sucess with epoxy is related to thickness, whether you are barrier coating a fg hull , or glueing a wood mast. You are going for the mils!

[lateral]

Proof of service with interprotect seems to be there.
I have always had trouble getting my head around it as a barrier coat because of the solvent. So I put 100% solids epoxy on, to at least 300 microns, then interprotect.
Actually if you take the actual epoxy content of interprotect, it is more expensive than west sys.
Read Wests sys test and conclusion of what solvent does to the permeability of epoxy. IMO, what sells interprotect is its ease of use. I would be interested to see wests test
substituting thinned epoxy with interprotect.

[Tony B]

Originally Posted by s/v Jedi

Another vote for Interlux Interprotect 2000E
Nick

+1 for Interlux.

West System was/is not designed as a paint or a 'barrier coat. It is a great adhesive and excellent for repairs but it was not meant to substitute as a paint. If you use it, will it work? Yes. Will you spend weeks on end sanding it smooth? Yes. If not, will it look like ****? yes.
There are barrier coats specifically designed to be, well, barrier coats.
This is like one of those "use the proper tool for the job" things.