ppg deltron questions
I am a newby trying to re-paint an old buick with black basecoat/clearcoat.
I've gotten the car down to bare metal, and applied DPLF primer. As DPLF is non-sanding, I am told that I should apply K36 Prima for the blocking/leveling. However, the p-sheet says that a sealer must be applied over K36 if you are using a DBC black basecoat.
What is the reason for the sealer? Is it to prevent sanding marks from swelling?
I am also concerned about putting on 5 different components (DPLF,K36,NCS2004, DBC, and DCU2002), in terms of shrink later on down the road, or having paint that is too thick... Are these concerns valid?
They are telling you the truth, but the truth can be so many shades of gray. The sealer over k36 is not nesasary but nice and a good idea. I would use black DPLF for a sealer(add 1/2 part 802 reducer) then DBC or you can skip the DBC. The black DPLF works great for a base coat. Another Idea that I would think about, is K36 is allmost white so you could go with a darker PPG 2k like 3056. Rock chips look hideus in black when the primer is white. Hope this helps. Ask away. I have been useing PPG for over 10 years. Don't worry about filmbuild, that stuff cost so much you can't aford to have to much filmbuild.
Last edited by 68-chevyman; 03-10-2006 at 08:19 PM.
In this paint system, the dp goes to metal and then you put the K36. If you let the dp dry for more than 1 week before you put k36 on it you must sand it, it has gone out of it's recoat window.
Basically, the DP stays opened for recoat for about 1 week at 70deg. Calculate that if it's warmer than that the opened time will shrink. I like to keep it to a few days. Its perfectly ok to sand the dp though if its been sitting on the car for a while. Don't hesitate to coat your car with dp once its bare, then do all the body work you want then just scuff it and continue with K36...If you do it by the book (ppg's book) you would then re-spray the sanded dp with another coat of dp and then spray the K36, but if you don't go through the dp when sanding (you only need to scuff) you can spray K36 on the sanded dp...
I only use dp as a sealer, so save your money and don't buy a sealer. When used as a sealer you add 1/2 part reducer to the mix. The goal of the sealer is to get the car to one even color and provide a substrate that will provide an even texture/absorbtion rate for the solvants of the topcoat. It's always a good idea...but keep in mind that K36 is also used as a sealer! So if your car is an even K36 color then you can skip the sealer, many body shops do...but what the hell, if you already have the dp, why not put it on as insurance. In general on good jobs I always use a sealer.
The sealer will go on like it was the first coat of basecoat. You mix your dp like you do normally and add 1/2 part reducer to it to help it flow. Spray one even coat of dp and let it flash for 30 minutes. Then start your basecoat coats. Use DBC basecoat and don't forget to add DX57 catalyst to your DBC to chemically harden it. Doing this will crosslink the base coat (hardening). This will help in two ways. Areas that you miss with the clear will hold up much better than if the basecoat was not crosslinked (in cracks between pannels etc) but most importantly it will prevent the basecoat from rippeling if god forbid you would sand through the clear when color sanding the job and had to repair the area with more basecoat and clear...
I would use 2021 as a clear coat, it's easier to use than the 2002 I find and it is as nice...Use dcx61 in the clear as a hardner and choose your reducer ackording to your shop and car surface temperature.
You will find K36 sands real nice. Protect yourself well, K36 and the clear coat are urethanes and contain isocyanates...One trick with any epoxy such as the DP is that it must be mixed real well. The error that is mos often made with epoxy is to not mix the catalyst in well enough. The ppg book stresses the importance to mechanically mix the dp in a shaker for 5 minutes! That's alot of shaking...Then let it induce 30 minutes (let it sit before shooting) if using the slow catalyst (I let it sit anyway, slow or fast, it does not hurt, only lets the chemical reaction take place before the solvants evaporate which is what it was designed to do.)
I have used ppg dplf and would like to thank you for solving one of my opps!. Like you said letting the dp sit for 30 min before shooting it. When I read your post a light went off lol. I sprayed dp right away and let sit for 30 min on the panel. Then I sprayed k36 opps. After sitting for a couple of months in k36 primer the k36 would lift in a few spots mainly in corners. I should have followed the directions a little closer. thanks.