epoxy and FG questions for redneck truck camper

[wysedav]

I'd recommend going to Nick Schade's website. He build strip kayaks and goes through all of the details on how to fiberglass. It's really easy, you probably didn't need a seal coat unless your going clear,sometimes it sucks the epoxy out of the fiberglass and leaves it a little white which isn't ideal if you're going clear. Put your fill coats on before you start sanding, wait a week or so before sanding so the epoxy is nice and hard, hit is with 60 grit and then 80. Paint away. If you get runs in the epoxy (which you shouldn't if you squeegee well) it's easiest to use a razor blade as a scraper while the epoxy is still green. i built a few boats and once you get the rhythm, it's pretty easy.

Good luck.

 

[MudFlap-TNT]

Thanks for all of the e-hand-holding.

I'm cranking right along now.

Did an all-over "seal coat", let cure, then a light wet-sand (using spray bottle, sanding block and paper towels).

Then picked a side and laid in the fiberglass, followed by three fill coats, all about 8hrs apart. Tedious, but not too difficult.

The only thing that didn't go quite as expected is I picked up a healthy "orange peel" texture with the fill coats.

As this was a vertical side, I had to apply the epoxy with a roller, and I erred on the side keeping the roller fairly dry, so very little squeegeeing was required. In some areas I did a little squeegeeing, others hardly at all, and the results were still the same. On the last coat, I tried a little "tipping" with foam brush. Looked better for a few seconds and then ... back came the texture. Maybe should have done that on previous coats?

Not a big deal. I'll knock down the high spots a little when I sand before prime & paint, and I don't really mind a little texture. Just a bit surprised that the texture got rougher with each fill coat layer.

Is that normal? Does it mean that my fiberglass will fly off when I least expect it? haha

 

[Tony Latham]

Is that normal? Does it mean that my fiberglass will fly off when I least expect it?

As my propane installer friend once said, "it shouldn't blow up."

Were you using rollers specific for glassing?

Me? I'm a steeley-eyed squeegee guy.

Tony

 

[Tom&Shelly]

The only thing that didn't go quite as expected is I picked up a healthy "orange peel" texture with the fill coats. ... Is that normal? Does it mean that my fiberglass will fly off when I least expect it? haha

I'll answer your second question when we finally have ours out and running!

Shelly and I were surprised at the surface appearance on ours as well, the first time we did it. Came right out with mild wet sanding though. Shelly does often tip off for me with a foam brush after I roll (with white rollers), and it makes it look a little better pre-sanding. Not convinced it's necessary though.

Yours is probably fine.

Tony, one of these days, I'll try a project your way, to see what the difference is. (I'll have to buy a circular sander first.)

Tom

 

[MudFlap-TNT]

Learning as we go.

The rollers I used were "high density foam" (bought from Raka). No nap, fuzz, etc. Since I'm working on vertical walls, I *think* that I have no choice but to roll on the epoxy. I'll tackle the roof last and will forego the roller there. Looking forward tackling that last surface.

Brought Mama out to look it over. She's used epoxy to make tiny little nick-nack stuff and she immediately said:
1. The texture is from very small bubbles in the epoxy and
2. You can get rid of them by applying a little heat with a heat gun while epoxy is still wet.

So add "heat gun to fresh epoxy" as another thing I've never done before, but will give it a try!

note to self: make sure insurance is up to date before taking heat gun to epoxy. =)

In the end, if there's a little texture left after priming and painting (semi-gloss white), I'm fine with that.

 

[MudFlap-TNT]

Did a little Google'ing after I posted the last note, and sure enough, heat seems to be the key.

Found a couple good videos:

and

On the first video, she also uses a toothpick to move the bubbles to the surface one by one. If the sides of my camper were 4 square inches instead of 100 square feet, I might give it a try, but since not, I'll try the heat gun.

Sure enough, the second video clearly shows the bubbles disappearing pretty quickly!

 

[Tony Latham]

Since I'm working on vertical walls, I *think* that I have no choice but to roll on the epoxy.

I get the vertical issue. For the front of my "roof" I applied it with a brush and then ran the squeegee over it. If I had had a Raka brush, I'm sure I would have used it.


Tony

 

[MudFlap-TNT]

Thanks for your help Tony.

One stressful part of this process is that once you pour the hardener into the epoxy, clocks start running.

On the first video I posted above, I was surprised that the girl mixed up a batch of epoxy, let it sit around for a while, then leisurely broke out the heat gun and zapped the bubbles in the mix cup. Heck, once I'm done mixing the epoxy, I'm practically running to the camper to get the epoxy applied ASAP. Of course, all the girl needed to do with her epoxy is pour it into a mold. How long does THAT take!

But as you've said, we're not launching rockets here, and it does appear that the process is a little more forgiving than one might expect...

 

[OP827]

Thanks for your help Tony.

One stressful part of this process is that once you pour the hardener into the epoxy, clocks start running.

On the first video I posted above, I was surprised that the girl mixed up a batch of epoxy, let it sit around for a while, then leisurely broke out the heat gun and zapped the bubbles in the mix cup. Heck, once I'm done mixing the epoxy, I'm practically running to the camper to get the epoxy applied ASAP. Of course, all the girl needed to do with her epoxy is pour it into a mold. How long does THAT take!

But as you've said, we're not launching rockets here, and it does appear that the process is a little more forgiving than one might expect...

I have to mention that it is possible to mix a large amount of epoxy and stir it for one minute and it will not go off unless you have poured it onto a surface for lamination within 2 or so minutes. Once it is on the laminating surface it will never go off since the heat is being dissipated. Later in the build I mixed about a quart of epoxy at a time and laminated large surfaces that way. The girl in the video could be using other type of epoxy designed for pouring (like table tops type) which has longer working time than traditional lamination 5:1 mix ratio epoxies that would go off faster. Lately I used newer 2:1 mix ratio generic epoxy that had at least twice curing time of traditional 5:1 epoxies. And then there are various speed hardeners... so it depends on a variety of factors.

 

[Tony Latham]

I was surprised that the girl mixed up a batch of epoxy...

I don't know what kind of epoxy she is using but I think I could get in a lotta trouble even with Raka's slow-set hardner.



Tony

 

[MudFlap-TNT]

Were you using rollers specific for glassing?

I think you were on to something, Tony (rollers).

I ran low on the rollers that I bought from Raka and picked some up off the shelf at local box store. "New" rollers looked/felt just like the old ones, but the bubble problem was worse with the new rollers, especially towards end of job after rollers were saturated and started to soften up. I guess they were lower density...

In the end, it will not be too big a problem. A light sanding seems to knock the top of the texture down nicely, leaving just a very small amount of texture, which is fine.

Only other issue with finish is the "selvage" edge of the fiberglass leaves a slight ridge in the epoxy. Plan to knock it down a bit with sanding and apply a little more epoxy.

I'm almost done with all sides of camper, leaving just the top. FINALLY, I get to do a horizontal surface!!!

 

[saltydawg-TNT]

Guys there is a few tricks for making mixed epoxy not kick off too fast. First and easiest after you mix dump it in to a disposable cookie sheet, it spreads out and the heat does not build up and make it kick. Next, refrigerate the epoxy and hardener, yup keep the jugs in the fridge then mix. Yes it gets thicker until it warms up but with in seconds of applying to the surface it is at the surface temp. Depending on what your doing it might make it a little trickier but it will add time before it kicks in the mixing cup, in my experience it gave me at least an extra 20 mins. You might want to make sure you are doing it in the right temp range for the epoxy thou at if on the colder side it can take for ever to cure all the way.

And in all honesty having the ability to heat the area after you lay out the epoxy is not a bad idea, and radiant heaters that go on 20lb propane tanks set about 10 to 15 feet away work great to help it cure.

 

[MudFlap-TNT]

Happy to report that I'm done (yay!) with the fiberglass!

Well, I have one more session of sanding, then I'm on to prime and paint in a day or two. Yay!

Looking back, the process was not as difficult as I expected.

Problems:
I had three small(ish) bubbles appear in the FG. They each measured about 1/4" by 1" (or less). Two were on an edge, perhaps caused by epoxy sinking into void in edge, displacing air, which rose and formed a bubble. One was on a flat area. Looked like a small raised "wrinkle" in FG cloth. Went at 'em with sander, then filled with thickened resin. No problem.

Advice for others:
Nothing much. Oh, I have this: early on, I would measure out resin in one small disposable cup, hardener in a second small disposable cup, and then pour them into a third disposable cup, mix, pour into paint tray and apply. All disposable cups were then ... disposed!

I quickly realized that (with appropriate size resin cup) I could measure resin in one cup, hardener in second cup, then pour hardener into resin cup and mix. So one less cup to throw out.

I did that for a day or two when my wife asked: Why don't you just put TWO marks on one cup. Add resin up to the lower mark, then switch over and put in hardener up to the second mark?

Well, duh! I told her that if I lost track or made a mistake in filling the cup, I might have to throw everything out, but I went ahead and started doing that and never had a problem.

FWIW, I didn't have an extra hand to mix resin for me, so I did it on my own, but this was fine.

I did end up switching over to electric sanders. "random orbital" and "finish" sanders. I like the finish sander best (orbital wants to walk around more), but I have lots of sanding disks for orbital that I'm trying to use up....

Lastly, I'm just glad that it is done. The FG work was quite time consuming. Lots of built in delays: Wait between coats of epoxy. Wait to sand. Etc.

FWIW, I used close to six gallons (total between the two) of resin and hardener. This was for an initial "seal coat", one "bond coat", and three "fill coats".

Many thanks to those on this list that offered their advice. The confidence that comes with having questions answered makes a big difference before you jump in and start mixing epoxy!

 

[Tony Latham]

I did that for a day or two when my wife asked: Why don't you just put TWO marks on one cup.

Pumps make life easier...

But good job. I suspec that fiberglassing is now part of your shop skills that'll be used in the future.

Tony

 

[Tom&Shelly]

Happy to report that I'm done (yay!) with the fiberglass! ...
Many thanks to those on this list that offered their advice. The confidence that comes with having questions answered makes a big difference before you jump in and start mixing epoxy!

The techniques that are successful for you are the right ones. Glad it worked well!

Tom

 

[saltydawg-TNT]

When I have done glass work in the past I tried pumps. Every pump I used failed, every one, I used west systems pumps. It caused issues on a few things, like epoxy taking weeks to cure and in one case after a week I heated the space to 90 degrees for 3 days.

I then started using the pour in to a cup to a line, add hardener to a line and mix method. Much faster and more accurate. If you use the plastic mixing cups from places like west marine or depot the epoxy will peel out after it cures and you can use the cup a second or third time.

Maybe for doing a few oz for feathering or patching pumps maybe be ok but pumping them 50 time or what ever it is to get 60 oz of resin sucks. And dont loose count

 

[Tony Latham]

Maybe for doing a few oz for feathering ...

I've mixed several gallons of Raka epoxy using their pumps in the last half-a-decade or so. No pump failures and no batch failures.

[youtube]BJZYGY2he1o[/youtube]

Big or little, they work for me.

Tony

 

[pchast]

I've used measured cups for large batches. I'll put a second inside the marked one so that the measured cup is always clean.

For small batches an inexpensive electronic scale is great for making the ratio right. The manufacturer's web site will provide weight ratios.

 

[MudFlap-TNT]

The techniques that are successful for you are the right ones. Glad it worked well!

Tom

Yep. Thanks again, Tom. You were very generous with your time in getting me going.

My $0.02 on the pumps: I used them, but also used the "cup in marked cup" technique as a check (read that somewhere). Sure enough, one time, I had a pump "burp" an air bubble out mid-pump. Another time, after not using one of the pumps for maybe a week, it "lost its prime" and when I went to fill my little cup, about half of the downstroke pumped air only. With the marked cup method, it was nice to be able to double check the volume and bring it right up to the line as needed.

A couple questions for Old Times Sake:

What do you do with the pumps at the end of project? Pull them out and pump what's in them back into jugs? Leave them in, but lock them in the "down" position?

I'm working on plans for a second whack at the camper-building piñata, but it'll be a couple years before I'm back doing FG (yay) again.

What is the shelf life for resin and hardener?

 

[Tom&Shelly]

A couple questions for Old Times Sake:

What do you do with the pumps at the end of project? Pull them out and pump what's in them back into jugs? Leave them in, but lock them in the "down" position?

I'm working on plans for a second whack at the camper-building piñata, but it'll be a couple years before I'm back doing FG (yay) again.

What is the shelf life for resin and hardener?

We just left the pumps in (in the up position) for maybe 6 months. I've been back at it recently using the epoxy for waterproofing and glue, etc. There seemed to be a little bit of white hardener (whatever that was--haven't read about it) at the very beginning, that I threw away, but other than that, it seems to keep well in the jugs with the pumps.

I wouldn't trust those pumps for amounts, especially after that. As you know, we use the double cup system.

Tom