Finished welding my skins on, ground down the welds (not pretty) sprayed DPL74LP epoxy primer on then after that was dried for about an hour, I put duraglass on. As soon as I started with the grater the duraglass peeled of in sheets. It looks like it didn't adhere to the paint. I don't think it is the duraglass because I used a metal plate to mix it on and it adhered to that. What could be the problem.

I don't think you let the epoxy cure long enough.

I would leave it overnight to be sure, then give it a quick scuff.

x2. The epoxy was still setting up when you put on the duraglass.

depending on the hardner you used you PPG says 1hr on one hardner(I believe its the 401) to overnight on the slower hardner(402). Regardless it should wait overnight before filler.

Also whats the metal temp? Without a good 70 degree metal temp that epoxy will NOT cure, it needs atleast 4hr of straight 70 degree metal temp.
The air and metal temp wont be the same unless your garage is kept at a constant temp all day long and night...Eric

I always duraglas over bare metal and weld joints and never have had a problem.

I always duraglas over bare metal and weld joints and never have had a problem.


Thats what I did. I took off the epoxy and put it right over the bare metal and weld seam. I have been doing body work for 30 years and never used an epoxy under my filler and never had a problem.

There's a learning curve when using fillers over epoxy and you made the most common mistake. Will your filler work just fine over bare metal-yeah. But is it better to do the filler work over a quality epoxy-yeah. It's hard to teach an old dog new tricks-and I went through the same thing back in the late 80's when PPG first started recomending this proceedure.

Ditto: Patience is a Virtue !
I still want to grab the 9" grinder with 36 grit disk to pre-prep an area
B-4 laying on the Mud. :(

it's hard to teach an old dog New Trix !

This is the first body work I am doing on a steel car in 15 years, before that it was mostly vettes. I have to get back into the groove with the steel, there are so many new ways to do things since the last time.

On EVERY restoration that we do here I epoxy prime the whole body inside and out after it is stripped to bare metal. Right over the rust holes and all......THEN I procede to do the metal replacement and promptly epoxy the ground down welded repair. I then move to the next rusted area and repeat the process. This keeps down the flash rust that would appear. I have found that using epoxy primer under any repairs extends the life of the repair. You just HAVE to make sure that the epoxy primer is completely dry before anything is put over it. I usually make sure that I let it sit at least overnight before filler.

In your case, it sounds to me like the epoxy was still breathing and popped the glass off. Wecome back to METAL cars.....:thumbsup:

Yea welcome back, I couldn't wait and now I kinda wish it was a vette. Very little rust problems.