Dave Tracy

Getting close to start painting and doing some final prep. I stripped my '64, gel coat, PPG DPLF epoxy primer, and K36 high build primer. I have been at this for years. One of the few flat areas on the car is the lower aspect of the doors. I have used guide coats while I have been block sanding. In spite of sanding with the guide coat, I scrutinize the contour by wiping wax and grease remover to produce a sheen and then look at the reflection of my neighbor's house on the panel. I see some irregularities in the panel and have continued to sand. I have sanded through to the gel coat in one area. Due to California's rules, the current PPG epoxy primer is DPLV which is a thicker formulation than the DPLF and seems to be similar the the K36. If I cover the panel with the DPLV to an adequate film thickness, should there be any concern of the thin areas of the underlying primer coats. Any advice is always appreciated. I will be using DPLF primer as a sealer and PPG DCC single stage ermine white urethane

DUB

Dave,

A little late now...but if you are getting close to exposing the gelcoat...you need to STOP and re-apply primer.

Also a lot late...I generally fill in the lower section of the 63-67 doors with VPA...and then block and block. This is so when I go and gelcoat...it will block out flat and actually strengthens the lower section of the door which is flimsy.

Also...I do not use epoxy on the gelcoat...I use a polyester primer. It has super filling capabilities. Seriously high build.

I do not know what to tell you on if you should or should not use the epoxy primer that is thicker (DPLV). I have concerns about that...especially if you are applying it on top of the K36 which is hard. I am thinking WAY DOWN THE ROAD...when it can show up.

Also...it has been a very long time since I broke through my gelcoat when blocking. It happens when I am blocking it...and I re-apply it again...but I do not get into it when I am sanding my polyester primer...to the point that I cut through it and see bare fiberglass again. When I have broke through the gelcoat and got into the bare fiberglass. It would all depend on where it happened. In some cases in the past when it did occur...I actually re-applied gelcoat back onto the exposed fiberglass and then re-applied my polyester primer...but the gelcoating was done AFTER I sanded the polyester primer back and removed the polyester primer so when I applied my gelcoat again...it did not get on top of my polyester primer...and the gelcoat was going back onto itself.

So..being in the basic center of a panel...to me is not good....versus it being right on an edge. The photo you showed does not appear to be down to the fiberglass...so re-applying the K36 should work and not show a 'ring-out' in time.

I do not know if this helped or made it worse.

DUB

Dave Tracy

Thank you DUB for your reply. You are right that I am to, not through, the gelcoat. I do have the DPLF epoxy primer that I was holding in reserve for my sealer coat. Both the DPLF and DPLV can be used as sealers so could you please elaborate on your concern with the DPLV over the hard K36?

DUB

Dave,
I have never used or know any of the characteristics of the DPLV, I have used the DPLF. But I usually only use it on the steel areas of a Corvette...such as the inner door of a 1963-1982.

I have..in the past...been burnt by the DP epoxy primers back in the day BEFORE they went to the DPLF formulation. I also had great success with it. It depended on what I was using it for.

When I as having issues with it...my local PPG rep...when we were both in a training class together....he told me that the epoxy primer could take up to 2 years to cure. And knowing when I was using it...if I tried to sand it....it was still soft and would easily clog my wet sand paper. THAT is when I changed my routine and stopped using it because I thought. If the body is hard and rigid....and I apply an epoxy primer that stays soft on it...and then apply a primer on it that will harden up...I was concerned that the soft layer would cause issues when curing out. And then when I used the epoxy as a sealer...I could come back in the next day after painting the car and even if I left the fans on all night ...I could see 'die-back' and the clear would actually have a slight haze in it.

I know many people who use the DPLF as a sealer. And have success in it. It has a lot to do with making sure you use the correct reducer ( a DT reducer if I am not mistaken) and apply it correctly and not dump it on.

SO....if you are going to use a DP epoxy for a sealer on the K36. Just follow the instructions on application and allowing it to flash off well before you apply the paint. I am not going to write NOT to use it..because I have used it in the past...and it worked. But with some glitches that did not make me happy I stopped. And remember ...I was using the old formula and did a few with the DPLF. It just is not how I do it any longer due to my paint system has a sealer that I love.

DUB

Dave Tracy

Thank you again for taking the time to reply DUB. I'm going to call the tech line this morning and will post my findings.

Dave Tracy

Talked to "Dave" at the PPG tech line and explained the situation. I was advised that all of the components are compatible with each other whether put over or under each other whether it be the DPLF epoxy primer, DPLV epoxy primer, K36, or DCC color.

DUB

I pretty much knew they are compatible. Glad to read that they said you are OK. Seems like you are on the way to completion.

DUB