MarTay6

I'm just about to the point in my JAE .21 Nitro build to start the sealing/finishing process. I will be using the West Systems epoxy finishing materials- the 105A epoxy resin with the 207SA hardener... also got the mini-pump set ordered with it to facilitate mixing.
I'd like some advice on applying it- as to best method. Not sure if I want to leave it clear or apply pigment, have to find out about that. Planning on applying it to one surface at a time, i.e., tops of hull/sponsons at a time from one batch, then turn all on their sides/apply another to make it easier. I did a search on the site here, but didn't really find an answer to my question.
Any guidance for me? I've not used this method of finishing before... my last experience with R/C nitro boats was 30 years ago with HobbyPoxy products, and I"ve forgotten everything I knew then!
Thanks in advance-
Wes

foodstick

First of all I am no expert, but I have built a few things that I glassed with this stuff..you will love it !

I personally get my cloth cut, and I like to brush it on the surface I will glass. I lay on the cloth and add more resin, I then lightly squeegee it until its all saturated, then I lightly squeegee ..pulling back out any excess resin.

I have heard of guys taking a new roll of toilet paper and rolling it on to pickup excess resin as well ...then pull off the saturated area of toilet paper and roll it again.

MarTay6

Hi, F/S-
Except that I won't be using fiberglass cloth on the wood... simply as a sealer/finishcoat. Glad to hear you like the product, though- I understand it's supposed to be very good stuff...
Wes

TCHedOff

This is just my .02 based on the 3 boats I've done in the last yr (all JAE type). Get yourself cheap epoxy brushes at your hobby store - they're cheap - like $1 (2?) for 4 in a pack.... they have coarse black bristles, w/silver-colored hollow tin handle (you can bend them to get under & around hidden areas that are hard to get at).

Wear disposable gloves (not for cleanliness - epoxy isnt good for you and exposure can create reactions over time/repeated exposure).... Apply epoxy, and wipe off with a disposable cloth that doesnt leave lint behind - I usually steal one of the wifes old dishcloths . Do small areas at a time (like 1 sponson per time/ just the outer tub 1 time; inner tub 1 time) so the epoxy doesnt kick off and start getting tacky before you get around to wiping off the excess. I've tried using a card, a razor blade etc to remove excess epoxy (as suggested by other posters) but didnt like.... too hard to get underside the radio box lip (and noticed some other issues).

Recoat and remove excess epoxy a 2nd time, and you're good to go.

You asked about pigment.... I've used alchohol base dyes on all 3 (the first boat, didnt like the result, so I painted it green ) Is this what you meant by pigment?

MarTay6

Hi, TCH-
Well, I was simply wondering if one wanted to paint the boat, it seems to me a good way would be to use pigment in the epoxy- that way you're adding minimum weight, I'd think... besides, epoxy is fuel proof, and most paints aren't. So I'm wondering the best way to paint it if I decided to do something other than clear.
Thanks for the other comments re. application, yeah- I agree with the working small areas. That's why I talked about only doing one surface at a time.
Wes

amax

The acid brush that TCHedOff described or a Foam Brush work best for applying, I like the foam brush because you can squeeze the extra epoxy out and use it to mop up any extra epoxy off the hull.

Set the parts and the epoxy out in the sun for 30 min to warm up, then give them about 5 min out of the sun before mixing epoxy. The heat will open the pours of the wood for better saturation and fewer air bubbles, and it makes the epoxy thinner so it flows out slicker and thinner.

There are Epoxy Pigments available that will work very well( google it), I would not recommend using Any Alcohol anything with epoxy as it will greatly slow down drying and and decrease Hardness and strength, When using alcohol epoxy dries to a rubbery state instead of a harder Plastic state. If you must thin Epoxy Acetone or Methyl Ethyl Ketone(MEK) are the best thing to use, but will also slow drying time down.

TCHedOff

The alchohol dyes I used arent mixed w/the epoxy (I'm sure AMAX is right about the results ). You buy them as a powder and mix w/alchohol (I use 1 qt jars for canning food) and apply - then let dry. Then apply your sealer coats of epoxy.

As a thought for you, MarTay6 there are also colors/pigments that can be added to your automotive clearcoat when you're ready to shoot on the clear (assuming you using a paint gun set up).... guy I run with has a couple of his boats done this way.... they a beautiful... you can see the wood grain, but it's tinted (in this case an orange that looks the color and depth of a tootsie pop).

wave waker

check youtube ther's a lot of video demo about this stuff....i'm presently using this west system...

ww

FurnalFlyer

oo Some advice I can share with this as i have built many Stock Outboard Hydroplanes with my father.

1. For the first coat add isopropanol (Rubbing Alchol) to thin it out. Enough to start making it milky white.
2. Next take a squeegee and dump some of the thinned out epoxy. Squeegeeing the epoxy into the wood makes sure that the pores of the wood fill in and helps prevent it from producing bubbles while it dries.
3. After the first coat dries, Use a foam roller (or brush) and apply a second coat of thinned epoxy, once rolled out take a bristle brush and go over the area just coated with long strokes (this will knock down the bubbles that are produced with the foam roller)
4. For a third coat use straight epoxy and roll it out and then follow it by brushing out the bubbles.
repeat step 4 to the desired liking.

If you are going to paint over the boat stop at step 4.

I hope this helps.

FurnalFlyer

Flyer Race Boats

mike walker

All the advise above is very good but if your using the 207 hardener I dont think it likes paint over it you may want check with West. But I could be wrong

dicko

You can paint over it, you just need to use an epoxy primer before you paint it.

Hydro Junkie

Just so everyone knows, the West Systems website specificly states NOT TO THIN WITH ANY SOLVENTS as it has adverse effects on the hardening properties as well as the final cure strength. They recommend heating the resin and catalist BEFORE MIXING and spread it while it's still hot.

ob nut

My Feedback: (1)

Been using West Systems for the past 5 years without problems. As already stated, using a foam brush to put on. Allow 30 mins soaking time. New brush and wipe off any extra. 1 hour later, another coat using the same process. 30 mins, wipe off again with a new brush. Didn't like the results when adding the epoxy pigments. Might not have had it mixed enough. Sure looks better when the pigment was added to the clear coat.

MarTay6

Thanks for all the inputs, folks- I guess everyone has their favorite ways, and one must figure out what works best for them. The one thing I would say, is that I agree with not using alcohol... West specifically states not to do so. If it works for you, o.k., but especially adding as much as was stated, I don't think would be a good idea... I certainly wouldn't attempt it. Overthinning materials that set up by a catalytic action is not something I'd want to attempt. While it may work sometimes, when/if it doesn't, the results could be a horrible mess to try to fix. Better to avoid potential problems in the first place.
Wes