epoxy on vertical surface - to thicken or not?

[chuck in WA]

Hi gents,

I'd like to apply fiberglass mat on a vertical surface. I'll be using epoxy. On one hand, I feel I should NOT mix in any thickeners so as to have the resin as thin as possible to fully wet out the glass. On the other hand, I can picture the thin mix dripping all down the side of the hull before the epoxy has a chance to kick, thus starving the glass anyway. Thoughts?

 

[ondarvr]

Re: epoxy on vertical surface - to thicken or not?

Buy the correct laminating epoxy for the job.

Epoxy can be a little more difficult to work with on a vertical surface, but you should be OK with the right one.

 

[chuck in WA]

Re: epoxy on vertical surface - to thicken or not?

The epoxy I have is from U.S. Composites. It's thicker than the one other epoxy I've used before (MAS, for building a wood kayak), but I still worry it may run on a vertical surface if un-thickened. Come to think of it however, I don't recall a big issue when doing the vertical sides of my kayak 10 years ago. Maybe I'll give it a try without any thickener and see how it goes. Thanks Ondarvr.

 

[Woodonglass]

Re: epoxy on vertical surface - to thicken or not?

Use a piece of Glass or plastic laminate and pre coat your cloth on the glass/laminate using a roller or a plastic spatula. Then Wet out the surface of the repair. Peel the patch off the glass and apply the patch and roll it out. You wont get any runs and you'll get great adhesion.

 

[Yacht Dr.]

Re: epoxy on vertical surface - to thicken or not?

Hi gents,

I'd like to apply fiberglass mat on a vertical surface. I'll be using epoxy. On one hand, I feel I should NOT mix in any thickeners so as to have the resin as thin as possible to fully wet out the glass. On the other hand, I can picture the thin mix dripping all down the side of the hull before the epoxy has a chance to kick, thus starving the glass anyway. Thoughts?

Whats the application if I can ask ..

For just an instant information I can say that Epoxy should be applied to the surface and allowed to "tack" before your lams.

Basically you need to pre-coat your surface with your epoxy .. then just at the Right time do your epoxy laminates over that. Sometimes its good to use "Peel-ply" over your lams.

With MAT your going to have problems .. even with 1708 you might encounter some Drainage ..

What product are you really looking at and for what application ..

YD.

PS. GENTS .. there are some among Iboaters that are of the Female persuasion .. just to let you know .

 

[chuck in WA]

Re: epoxy on vertical surface - to thicken or not?

Thanks again ladies and gents. I went ahead with the unthickened resin and 1 1/2 oz CSM today (before I had a chance to read the last 2 replys, lol). It seemed to work out well. Todays portion of the project simply entailed laying 2 segments of CSM, each about 5" x 15". Since they were so small, I simply rolled them up, dunked them in the epoxy I had mixed in a plastic bowl, and once they were completely soaked unrolled them, removed the excess resin, and applied them. I then went over them with a grooved roller and squeege to make sure there was no trapped air underneath. I did get some drips, but nothing serious - I just had to wipe it up every 15 minutes or so for the first hour until the resin firmed up.

The projects (I have two going on at once) are simply "fiberglass training projects" for me, for some practice before I get to my "real" project boat (if I ever get there). If they turn out well, great; if not, no big deal either. This is more about experimenting with and educating myself about various cloths, fillers, techniques, etc. I'm currently working on an 8' dinghy which has a few holes in it, as well as an old gutted Sea Doo hull that my buddy wants to use as a "trailer" of sorts behind his running Sea Doo. The Sea Doo hull needs to be patched in the areas where all the old thru-hulls went for water intake, drive shaft, exhaust, etc. so it will float on its own.

I elected to use CSM for a couple of areas on the dinghy which had holes, but were inaccessable from the inside. My thinking was that the mat would hold resin better than cloth without allowing it to run through the holes in the hull (into the inaccessable area) and would provide a solid surface to go over with the cloth. Now that I have a "sealed" substrate, I pland to sand much of the CSM off and apply a few layers of 6 oz cloth (since I have some leftover from a previous kayak project) to beef it up. After the cloth layers are complete, I have both microballoons and a fairing compound to experiment with for the faring step. I'm not really sure what the difference between them is, as they both look very similar when you take the lid off each bucket and look.

 

[chuck in WA]

Re: epoxy on vertical surface - to thicken or not?

Before and after photos from today. I did end up with some air underneath a section of the mat, as you can possibly see in the close up photo. I'm guessing that it happened because the temps were rising outisde as the epoxy was curing, and expanded the air in the now closed chamber of the boat, lifting the mat.

 

[chuck in WA]

Re: epoxy on vertical surface - to thicken or not?

As long as I'm posting pics, here's a before and after of the repair to the bow I did last week. It's just a peanut butter mix of epoxy, cabosil, and 1/4" chopped fiber.

 

[Yacht Dr.]

Re: epoxy on vertical surface - to thicken or not?

Did you just layup epoxy mat right over Gelcoat .... ?

YD.

PS. mini bump ..

 

[chuck in WA]

Re: epoxy on vertical surface - to thicken or not?

Sanded with random orbit sander 80 grit until repair area was dull "chalky" white, then wiped down with an Interlux epoxy wash product (again, leftover from kayak construction). Hopefully that will be sufficent?