Question re gel coat repair

[Ron in BC]

Originally Posted by Wig

It can be time consuming depending on the depth of the repair as the gel coat is pretty thin requiring several coats.

I'm a little puzzled by that. If you look at the photos in post #4 you'll see that the heavy poly holds the gelcoat in place. (and leaves a smooth shiny surface) Once in a while I've under filled a divot and had to top it up a bit but I've never had to do anything more than that.

It's normally the opposite that you have to watch out for. Putting too much gelcoat on and ending up with a repair that needs sanding down. Get it perfect and it's one and done.

Ron

[Wig]

Hey Ron,
Like I said I’m not a great craftsman. I did the poly method but still had some slight imperfections(air holes)so I added some more gei coat and had to do a little sanding. It was my first attempt and like anything else I’m sure the results will improve with experience.

[Ron in BC]

Yes, sounds like that was a pretty good first try. It is one of those things that practice certainly does improve results.

I don't know how much MEK you used but a little bit goes a long way. Not only obviously how fast the resin starts curing but it makes it more runny. I use a standard amount for all chip repairs, no % mixtures and curing time tables. 3 drops of MEK in 1 teaspoon of gelcoat. Doesn't make it too runny.

I also use a small stick, not a paint brush to place the gelcoat in the divot.

When using my finger to roll the poly upwards I watch for any bubbles and push them up and out.

Sounds like a lot of work but when you've done it a couple of times it takes just seconds to do.

Great that you tried a DIY repair. Hope you don't have any further damage to repair but if you do I think that it'll go faster and better. As that annoying saying goes, "practice makes perfect."

Ron

[Wig]

Hey Ron,
Thanks for the ratio, you’re right a little goes a long way. I have a 16 oz can of gel coat and if I’m lucky it will probably be a lifetime supply.

[sofmerc]

Originally Posted by Wig

Hey Ron,
Thanks for the ratio, you’re right a little goes a long way. I have a 16 oz can of gel coat and if I’m lucky it will probably be a lifetime supply.

gelcoat goes bad. Shelf life is debatable but...not more than a year or so...

[Ron in BC]

Yes, nothing last forever but the year or so is somewhat flexible. I store mine sitting on cold concrete in darkness and I've had usable gelcoat well past one year, more than 2 actually.

What doesn't last is the catalyst, MEK peroxide. Being a peroxide it'll break down and weaken much sooner than the usability of the gelcoat. It's very inexpensive and I never use any that's of an uncertain age.

Ron

[CharlesPou]

great thread, I've read it 2x's now and starting to soak in lols.

my damage is more widespread, tire blowout, loose tire flapping on side of trailer. I think no structural damage. I've done fiberglass repair before, structural repair, but never gelcoat. my repair estimates so far look like maybe $1,500, and leaving my trailer at shop for a week or so. maybe covered by insurance with $500 deductible?

I didn't realize could paint on gelcoat with brush, sand it down, maybe repeat, and finally wet sand to polish and done. so far, I read to buy gelcoat with wax so will dry nontacky, and marine tex is not gelcoat, so probably should avoid marine tex.

so, appears maybe doable, just lot of time, which I have plenty of haha.

any and all comments welcomed. cheers

[Ron in BC]

Originally Posted by CharlesPou

I didn't realize could paint on gelcoat with brush, sand it down, maybe repeat,

Don't do that. Use heavy poly as shown earlier in the thread. Use the right amout of gelcoat and you'll have much less work


and finally wet sand to polish and done. so far, I read to buy gelcoat with wax so will dry nontacky, and marine tex is not gelcoat, so probably should avoid marine tex.

Yes, absolutely stay away from marine tex, this is purely a gelcoat repair.

Waxed or unwaxed gelcoat is only a factor when it's going to cure in open air.

Waxed gelcoat requires scuffing before another coat can be applied.

Unwaxed gelcoat, when covered with poly, with be tack free.

Hopes this clarifies the situation.

Ron

[TWebs46]

Originally Posted by CharlesPou

great thread, I've read it 2x's now and starting to soak in lols.

my damage is more widespread, tire blowout, loose tire flapping on side of trailer. I think no structural damage. I've done fiberglass repair before, structural repair, but never gelcoat. my repair estimates so far look like maybe $1,500, and leaving my trailer at shop for a week or so. maybe covered by insurance with $500 deductible?

I didn't realize could paint on gelcoat with brush, sand it down, maybe repeat, and finally wet sand to polish and done. so far, I read to buy gelcoat with wax so will dry nontacky, and marine tex is not gelcoat, so probably should avoid marine tex.

so, appears maybe doable, just lot of time, which I have plenty of haha.

any and all comments welcomed. cheers

Charles,

A liter of color matched gel coat from ETI cost me $39 (US) including shipping. That will save a lot of time color matching.

Tom

[CharlesPou]

thanks for replies, Ron I guess you saw pics, this is not small scratch. I can't imagine being able to roll poly over these area and not have mess. maybe with some experience, sure, but I have no experience, and no confidence will work for me. just seems easier to paint it on, sand it down. good clarification on waxed vs unwaxed gelcoat. I wonder now if ETI gelcoat is waxed or unwaxed?, another complication?

obviously, if I was doing this repair over and over, like at fiberglass shop, I would learn how to do the poly roll method, but hopefully, I won't be doing this repair often, maybe never again. this is 1st tire blowout damage in over 16 years of pulling fiberglass trailers, Casita approx 11 years plus, Escape approx 4 years plus.

Tom, I contacted ETI and submitted after sales support ticket. I have to say, in the past I have had little success using this method. all I get is email acknowledgement and nothing after that. how did you contact ETI to place your order?

cheers

[DanandDaphne]

Originally Posted by MVA

Will you be doing a demo at the rally next year?
I thought I recalled that you were going to do a demo at the rally this past year and it was going to be recorded. If so, was the recording posted?

I would also be interested in seeing it. We have some chips on the roof, not chips from an impact but just a couple of places where the gel coat has little divots I am guessing maybe drips of sweat from the person spraying the mold or some other contaminant.

I get what your technique is, it doesn't sound too hard especially on the roof where the gel coat won't run, probably don't necessarily need to tape it on a horizontal surface.

[Ron in BC]

Originally Posted by CharlesPou

I can't imagine being able to roll poly over these area and not have mess. maybe with some experience,

I wonder now if ETI gelcoat is waxed or unwaxed?, another complication?

The area by the wheel would easily lend itself to using poly sheet.

This basically is a no mess technique. The poly is hinged at bottom with tape and taped at the edges. Small amounts are applied and the poly is smoothed and the air worked out as you work upwards. There should be zero mess.

It doesn't matter what ETI used. Before doing anything you would wash the area with acetone. If there was wax, or wax from waxing, it'd be removed.

Originally Posted by DanandDaphne

I would also be interested in seeing it. We have some chips on the roof, not chips from an impact but just a couple of places where the gel coat has little divots I am guessing maybe drips of sweat from the person spraying the mold or some other contaminant.

I get what your technique is, it doesn't sound too hard especially on the roof where the gel coat won't run, probably don't necessarily need to tape it on a horizontal surface.

ETI did have a camera setup and I thought that there would be a recording for others to view but unfortunately that wasn't the case.

I still use poly on horizontal surfaces. Put the right amount on, pull the ply off and you might have a repair that's hard to spot or requires very minimal smoothing. Dabbing on drops doesn't give the same good results.

Yup, drips of sweat falling out of the respirator will do it. So will a drip from the spray gun. In my university job we'd make metal flake custom bodies for dune buggies etc. One drip and the part became a second.

Ron

[DanandDaphne]

Originally Posted by Ron in BC

ETI did have a camera setup and I thought that there would be a recording for others to view but unfortunately that wasn't the case.

I still use poly on horizontal surfaces. Put the right amount on, pull the ply off and you might have a repair that's hard to spot or requires very minimal smoothing. Dabbing on drops doesn't give the same good results.

Yup, drips of sweat falling out of the respirator will do it. So will a drip from the spray gun. In my university job we'd make metal flake custom bodies for dune buggies etc. One drip and the part became a second.

Ron

What I meant was the tape hinge might not be necessary not the poly sheet, I understand the sheet is to smooth and flatten the gel coat.

What is the poly sheet you use, something like a stiff plastic bag?

[Ron in BC]

For many years I used acetate sheets, the kind used on overhead projectors from yesteryear.

I've also used poly sheet. Thickness matters. For example if you used something like a dry cleaner bag it would likely wrinkle and not give a nice smooth surface.

When I use poly sheet it's from leftover vapor barrier poly. Much thicker than a plastic bag. I've seen some poly bags that were heavier than filmy bags and they'd be suitable.

Ron

[CharlesPou]

I have questions about poly sheet too. where do you get it? I assume stiff, so how do you handle areas with compound curves. yes, the side of the trailer is flat, but some of the damage goes from the wheel well up to the side of the body. maybe you do the flat surface with the poly sheet, and the rest with brush on, sand, repeat, and polish? IDK

yes I know to clean well, water, some sort of solvent to remove wax and tire black. then maybe rough surface before applying gelcoat. I keep thinking about poly sheet method, getting closer, but not there yet lols. cheers

[Ron in BC]

I can't tell you where to find suitable poly. Stiff is probably the wrong term. It's not stiff like sheet acrylic, it's still flexible and floppy. Best bet would be to look for a suitable plastic bag.

Yes, it works best on flat surfaces. It appears to me that is where the most visible damage is and the area that you want to end up perfect.

Sometimes you just have to improvise. I've used strips on curved surfaces. You don't get that smooth almost perfect result you can get on a flat surface but it does make a better more consistent surface than brushing does.

Your damage really is the simplest kind of damage. No structural repair required and no deep damage requiring filling before the finish gelcoat is applied.

Ron

Ron

[CharlesPou]

so I'm racking my brain about poly sheet? I go to my local WalMart and see some poly sheet covering up an area they are remodeling, and thought maybe that's it. was fairly heavy duty, but flexible. then I looked around store to see what I could find, and found probably the same stuff, but for $30 I get 10' x 25" 6 mil, so way too much. question: I'm on the right track? IDK cheers

[Ron in BC]

Wow, expensive vapor barrier. For less than that I can get a 500 s.f. roll here.

I measured what I've used in the past. It was 6 mil.

Just keep your eyes open for a clear plastic bag a little thicker than a filmy one. You need clear because that lets you see if there's any trapped air and if there is you smooth upwards with your finger and move the air up and out.

Ron

[CharlesPou]

I search Amazon and find 6 mil Greenhouse Plastic Film Sheeting 6.5 x 6.5ft for only approx $15, so looks like this is it? so next question: I'm applying gelcoat with poly sheeting area approx 1' square, using fingers to smooth out seems like would be hard not to leave channels, so maybe use a bakers rolling pin? any and all comments welcomed. cheers

[Ron in BC]

Whatever works.

It's pretty forgiving. In your case it could be more the flat of your hand, a short length of stick or a roller.

At the end of the day there's little risk of a disaster. Gelcoat is relatively soft and sands very easily. If you have to do a second or third try it's really not a big deal.

Using a roller. That gave me a flashback to the time I used a plastic roller on a clear resin table top. Pushed a little too hard, the roller snapped and punctured the thin poly and splashed resin everywhere. Never made that mistake again.

Ron