Paining car

[kram350kram]

For those in the know, best high build over a soda blasted body? Urethane, polyurethane, epoxy, 2K? Thanks for any input.

[TurboFource]

It seems that I have read to use epoxy primer on fiberglass……but I am no expert on this….

[rjbaren]

I have no idea if this is even a good idea but for what it is worth, how about Barrier coat from the marine industry?  It is a two part epoxy system, sand-able, and made to go on fiberglass.  Interlux, Total Protect, and Pettit Protect, are three brands out there I have heard of.  I used Interlux on bare my boat bottom like twelve years ago and it is still there doing it's job.  Maybe worth looking into?

[jbcollier]

Lotus fibreglass was of questionable quality when new and 50 years aging and exposure haven't helped.  There is no magic spray on product that will permanently cover the problem.  You need to recover the body with veil/tissue cloth and reinforce known problem areas such around door handles, a-pillars, etc.

[BDA]

By "tissue cloth" are you talking about woven fiberglass? I would advise against woven cloth because it's very difficult to keep the weave from bleeding through the paint. I would advise the veil (mat) you mentioned.

Trying to shorten a long boring story: as part of a repair and repaint, a buddy and I agreed that a layer of fine cloth would be good because it's much easier to repair fiberglass if you have all the pieces and the thought was that the cloth would help in that regard. My buddy did the work and then painted the car. He said he tried all sorts of things to fill in the weave but nothing worked. When I rebuilt the car, I put a layer of veil on the doors and the boot and bonnet lids (I whish I had put two layers). I suppose I was too lazy to cover the rest of the car with veil but there are places on the body where the cloth he put on shows through. You have to look pretty close and it doesn't really bother me but if I had known at the time, I would have had him use the veil instead.

Your advise to reinforce known problem areas is obviously a good one. In addition to the top of the 'A' pillar, I would add the inner part of the rain gutter around the engine compartment - especially the rear over the bumper which is pretty flimsy on my TCS. I thought about doing that but I didn't. Another in a long list of things I wished I had done.

[kram350kram]

Thanks for that. So veil is a very thin "cloth" giving strength and a smooth surface hiding some surface imperfections? Any recommendation on a resin? Been using polyester for repairs, seems to adhere  pretty well to prepared surfaces.

[Pfreen]

My paint looks great after 5 years on a 1974 tcs.  This photo is of the car going to the paint shop in 2016.
I had ground out and veiled the cracks on the bonnet and trunk lid.

The car was stripped by sanding, filler, high build 2k primer and blocking (multiple coats) and ppg concept single stage paint.
I would personally strip the car and prime with epoxy.  It helps the 2k adhere.

The concept single stage paint is color sanded and polished after a month or so of drying.

[dakazman]

  If your down to bare glass the thin veil may be your best course of action .
Here is a wealth of glass courses. https://www.fibreglast.com/category/Learning_Center

   I painted mine with a 2k polyester primer, then a sealer.  It looked good at first, however with temp changes the paint shrinks at a different rate than the glass fibers. I will be repairing some others panels using the thin veil on them. Available here: https://www.fibreglast.com/category/s?keyword=Thin+veil.
Dakazman

[BDA]

There are different names thrown around so be clearer. I've always considered "veil" to be the lightest or very light mat but then when I was working on my car, I only concerned myself with mat so some might consider there could be a veil cloth. To be clear, I advise veil mat NOT (woven) cloth.

Maybe I should also clarify that although having all the pieces after an accident would be a good thing, I don't think the hassle of covering the car in woven cloth is worth the effort. Thankfully I haven't been in an accident to test that assumption.

As for resin, I just used what I got from a home improvement store which is polyester. There are others here who have posted about the ins and outs of different resins and which are appropriate for different uses. You might do a search on the forum for key words like "epoxy", "resin", or "polyester" to see what they say. I would say that my glass work has held for a long time so it can't be too bad but I make no claim it was the best resin.

Thankfully, D'man posted some good technical information!

[Kendo]

I’ve been having good results with first shooting a high build polyester primer. Duratec works really well, sands smooth very nicely. Then a 2k epoxy primer, then basecoat, clearcoat.

You’ll still want to veil (tissue mat glass) over any DPO cloth repairs.

[jbcollier]

Veil/tissue is not woven.  It's a mat of cut strands.

[dakazman]

  John is correct , it’s a mat as shown in my link.
.

Veil/tissue is not woven.  It's a mat of cut strands.

  Also , the glass used 50 years ago was very porous. I’ll try to do a video of the painted side of the boot I just acquired yesterday, Thanks Bert! 😃. It has sprayed on black paint that will be a perfect contract agent of the glass fibers as they lay. Sanding shortens the loose strands of the mat. I will not sand the strands but scrap with a bent utility knife blade and a bent razor blade.  I don’t have much experience making videos but I hope to show why these fibers move under any type primer.
  I tried to show the minuscule fibers lifting or not laying in the resin . Exposed by sanding.
  Using the this veil mat should fix this problem.
The second pic shows a better flaw in the reflection of the finish. I did achieve a better finish by resending with 1500. I did not polish it up yet but placed in the sun to see if Ivan see any flaws reappear. So far all good.
Dakazman
 

[Richard48Y]

For all panels that have been soda blasted begin with a "Holdtight" wash!
This has been discussed at length on other forums and the consensus is that it is a critical step for long term paint adhesion.

https://holdtight.com

[dakazman]

   Richard,
No mention of use on 1/8” fiberglass in video, steel,  yes. 

 I’m still interested, so do you have a link to the forum mentioned or some pics of panels?

  Dakazman

[Richard48Y]

From a Pro blasting site found after a short search, "HoldTight 102 will increase primer adhesion by up to 70%".

https://www.theblastmasters.com/Our-Advantages.html

Fiberglass tends to be an afterthought in the painting world but the same cleaning is required as if it were steel.
I will be soda bla$ting my entire car so looked into this pretty hard.
Lots of threads on the 'Net warning that soda blasting leads to poor paint adhesion.
My research found those threads to be very out of date.
I found none claiming problems after use of Holdtight.
Seems to be cheap insurance.