Cracking and Crazing

[gearbox]

It's been awhile since I have done fiberglass work, but is there anything new on the market to address the cracking and crazing of the gel coat? Or are we still grinding out each crack, filling it with fiberglass, then tissuing the entire car and sand it down again until its almost all gone?

I found a website that showed a guy completely covering his Elan with Bondo and then sanding it all down, leaving a very thin layer on the gel coat. I have to believe that the gelcoat cracks, even a hairline, will eventually surface, but not sure. Also there is a product made by Evercoat, a two part Polyester high build primer surfacer that the Corvette guys rave about. It still seems like it sprays on a layer of bondo like material and I guess if the bondo works, this should as well. Any first hand information out there? Thanks Allan

[KevJ+2]

Hi Allan,
There is quite an in depth discussion on this at the moment on Body Prep and painting ABC help, in the body / chassis section.
Just don't do any willy waving apparantly
Kev.

[Gordon Sauer]

Yes, that other discussion is addressing your type questions. I will say crazing seems to suggest a broader difficulty that to me would require the extensiveness of a full retissue, I use cloth like used in model airplanes- thin and without the build of mar when you don't need the build. Cloth is also stronger than mat. But a crack here or there I think can be addressed.Yes, that other discussion is addressing your type questions. With a single crack I've had good success, as long as the final color matches, with gouging out the crack and filling it as mentioned in the other post, with a resin/ fiber powder mix. The powder is available in the boating industry. Gordon sauer

[Gordon Sauer]

OK, just as an aside, I tried to get back to this topic because I wanted to add something and when I put in "cracking and crazing" it did not come up. When I put that into Google followed by lotus elan dot net then it came right up so you might use the exact words that were given to you in the other post. I had wanted to go on that of course you have to find the source of the crack, in my case putting the freshly painted hood down on a too hi brake line coming off the servo on my +2. Gordon Sauer

[Grizzly]

I don't want to start a big thing here too but get the paint off before assessing how bad it is, the original paint used by Lotus dries out / cracks / flakes off making it look WAY worse than it is. Because the Resin is 70% transparent the old cracks stand out as Black lines so are easy to see (the capillary action draws moisture in meaning the polyester starts to rot turning black which stands out against the Orange/Tan GRP).

Fresh damage is a different can of worms (those cracks are white, bit harder to see the small ones but still easy enough if you follow it back from the impact site)

The way you have to look at it is any GRP crack is there for a reason (often Flexing or Voids (bubbles in the hand laid grp) or badly bonded seams or too much chassis twist etc etc), if you fix the reason its there it won't come back when you repair it.

Btw, we had a demo of Everglass/Glasslite (think thats what it was called) looked quite good was almost like very fine fiber strand filler. Not my thing as i like to remove cracks completely and rebuild but i can see how it could be good to remove fine gel coat cracks and holes. I'd prefer to use that stuff (cut the crack out with a blade first i'd guess) than to do the same thing with just resin (Resin is very brittle on its own so would have no strength)

[gearbox]

Have been steadily sanding the layers off the car and the hairline cracks are all over the nose, fenders, and trunk lid. Surprisingly very few on the quarters and doors. But the cracks are numerous, I mean about every square inch and will take months to cut out each one and glass over. Just looking to see if any of the new products may make this job easier. Even if I carve out all the larger cracks and fill them with resin and fiberglass powder, there are a million of these smaller fractures. Will these be adequately covered by the tissue and hold up in the long run?

[Gordon Sauer]

I'm sure grizzly will weigh in on this but with that much damage in those areas I would grind all that out and relay cloth/tissue and build that whole surface up fresh.Gordon Sauer

[Geoffers71]

Yes, in such a bad case (and I've had much worse on a Europa I once had) the only way to resolve is to grind out the whole area back to the mat. No use tackling every crack on its own, just grind out the whole area. Make sure you get all of the cracks. Then at least two layers of tissue and resin and then a skim of P38 or similar. Re-profiling is a long careful process needing much patience, filling and profiling using a flexible long board and graphite guide coats to highlight high/low points. If necessary you can re-inforce the back of the panel with extra resin and mat.

[reb53]

Yes, in such a bad case (and I've had much worse on a Europa I once had) the only way to resolve is to grind out the whole area back to the mat. No use tackling every crack on its own, just grind out the whole area. Make sure you get all of the cracks. Then at least two layers of tissue and resin and then a skim of P38 or similar. Re-profiling is a long careful process needing much patience, filling and profiling using a flexible long board and graphite guide coats to highlight high/low points. If necessary you can re-inforce the back of the panel with extra resin and mat.

+1

I did my car in 1991, including all of each door, and have yet to have a single crack reappear.
I suspect scrupulous shimming of the body back onto a new chassis has helped by ensuring there were no inbuilt stresses once it went back on the road.
Don't know if it still exists, but after a lot of experimentation I found David's filler to work best as it wasn't too hard, or too soft, ( as the actress said to the Bishop.......).

Ralph.

P.S. I could go into detail, but only if you're really interested as I don't think anyone listens to me......

[Grizzly]

Yep, thats nasty.

Do you have much warp to the panels? That is past even just re-tissue imho, there not just Gel cracks they look like the Resin has dried out and failed.

Maybe worth grinding one out and see how deep it goes? But yes i agree all that has to come out don't just tissue over it and hope they don't come back.

[Grizzly]

I'm sure grizzly will weigh in on this but with that much damage in those areas I would grind all that out and relay cloth/tissue and build that whole surface up fresh.Gordon Sauer

Gordon, I deal with more Damp climate issues (osmosis etc, i'd want the GRP open for as little time as possible but in a warmer/drier climate you don't have to worry so much about moisture), me telling you how to repair sun damage is like some one from a warmer climate telling me how to repair moisture damage. You may well re-glass allot of that car but on the other thread (the guy from the UK) it was put across like that's the same with every car in every climate and its just not.

That said... Damage is damage, remove the damage and re-glass it back.

[gearbox]

Sigh........ I was afraid of that, but in for a penny, in for a pound, and it is time to soldier on lol. Puts back my schedule for another year, but I rather do it right than half assed. Plan on keeping this car for a very long time and maybe even passing it on to the kids. The panels are surprisingly straight with no warping. So from what I am hearing it would be best to tissue the entire car. I have done this before, but decades ago. So to get this right, I take down the entire panel down below the gel coat and stress cracks. layer the veil on the panel and sand smooth, but two layers of tissue? Do I layer the two layers of tissue and then sand or sand one and then do it again? I just found out that the Slick Sand surfacer will not bond directly to fiberglass and I will have to use a epoxy primer like DPL90. But what would you fellows recommend to seal the fiberglass after the tissuing? I have one fender and the trunk lid done so far and I need to speed up my progress, but need the feeling to return to my hands first. Figure completely down to gel coat in a week, and then another week to sand off all the gel coat, then another three weeks for the veil. I'm having so much fun I can't stand myself.

[BullAndrew]

I guess this counts as bit more that just cracking and crazing, and what a repair $%" not.

I knew the wing would need significant repair but I thought the previous owner had done a proper repair from inside, well it almost looked like that !! I was a bit confused at how dark the inside repair was , I got the DA out to clean it up and found a small lift in the repair patch, pulled it with my fingers and off it came, it was dark because the repair had been straight on to the dirty wing.

Anyway probably a good lesson don't trust previous repairs unless you know who did them and the quality of their work. It might take a little longer but do it yourself then it only your standards you have to live up to. I am going to clean and repair from the back to stabilise the wing, then I will grind out the top and layup a new wing with mat and tissue. I will post the updates as it comes together

[gearbox]

Lol, the car I am working on, I thought, was an untouched barn find, but it too had the front right quarter nose sectioned in. While the outside looked straight, the inside was bonded on by a butcher. The seams were just bonded with a 3" wide strip of fiberglass on both sides in the wheel well and nose, and there was a 1/2" gap in the parts. The good news was that they didn't bother to clean the area they were bonding and the fiberglass strip pulled off like packaging tape.

I'm committed in tissuing the entire car at this point but my question is after sanding off the gel coat and through the crazing, and then layering on a single layer of veil, tissue, csm, how far do I then sand the tissue? Trying to get csm completely flat will eventually break through I would think. Do I just get the contours right and then bondo the surface imperfections? I'm also looking into the new ever coat product called slick sand, which appears to be a self leveling spray on bondo. But it doesn't stick on fiberglass, so I will need to epoxy prime the part first. Any help would be appreciated. Thanks Allan

[BullAndrew]

Hi Allan,

I ran another post at the start of the month regarding tissueing, take a look at

"Body Prep and Painting ABC help" in this section so interesting feed back, like you I am thinking that once repaired a tissue cover would finish the surface before starting the preparation for painting.

Andrew