Think I'm being ********ed here but I'll throw it out and see. Anybody shoot DBC black over K-36 lately? I paint quite a few Harleys and the color of choice is black. Just had the 3rd bike come back in the last year for tiny blistering in the base coat..WTF! only in the black color, even next to a flame its only in the black. Paint rep for PPG says read the fine print you can't use DBC black over K-36. I have two P bulletens and no mention anywhere about this. This really ****s ,I have to repaint these at my expense and to top it off they all have some extensive flame work to reproduce.. So any painters out there been through this? is it my fault for not having a up to date P sheet? Haven't heard back from rep again....Anybody??
I have always been told (and I always do what I am told) that to ensure that this does not happen seal the K36 with Dp90 (black) before the DBC goes on. I've done that on my last 9 paint jobs and never had any problem with blisters, bleed through, chipping or anything else. I know it's another step and not inexpensive (cha-ching, cha-ching) but it's excellent insurance against these issues. My .02 worth
Thats the problem, nobody told me or I would have. Seems crazy to sandwich urathane between epoxy but if it works. I've been using DBU and switched to DBC thinking I would get a better product. Paint work is the most frustrating and most rewarding work there is.
First: why the hell are you using K-36? It's ****. Second: Yes I seal all my primer with epoxy as a sealer, or full strength & water sand it, before shooting paint. ~ Paul aka "Tha Driver" Headline: APATHY RUNS RAMPANT - Nobody cares.
Exactly my thots...I use NCP 250 or 270...much better than k-36...never have any problems with blisters or bleed-thru... R-
For some reason K36/38 both have to be sealed before shooting DBU/DBC Black....it is listed on the P-sheets for both that I have.
It's written in red on both P sheets. Must be sealed when top coating with DBC black. What other issues are you guys haveing with K36? I'm haveing none.
I'm not using it (haven't for *some* time), but have seen shrinkage before - even though I don't rush the drying/blocking process. And I *really* hate shrinkage!! LOL! ~ Paul aka "Tha Driver" Remember 1/2 of the population is below average.
Years back they used to list on the P sheets a way to mix K36 as a sealer as well. I blieve it was less product to hardener with some reducer. maybe 3:1:1/2 . Its not all that ****ty of a product, but price reflects quality levels. I like NCP as well and if you havent tried the NCS sealer, do it now.
I have used all the products you're all talking about extensively and daily. The bottom line is that K-36 ****s. Shrinkage is the main problem, film-build another. To get a high build means a very rough starting finish to sand on. We recently switched to the "Velocity" line...3055 primer and 3022, etc., sealers. The sealers only come white and light and dark grey. The primer sands really nice, no shrinkage, fast dry times, smooth finish, and rapid film build with no side effects. NCS sealer never seems to lay flat. The texture shows through the finished product. DP90 or others are not really recommended as sealers. Yes, they can be used as such but costly and better stuff is out there. Using K36 as a sealer was intended as a "wet-on-wet" application. You need to mix it with some Concept to get it to work. Tried it once and too much time, $, and trouble. The Velocity clears are also worth their price. Sometimes time is an issue in the prototype shop I'm in. While not for overall stuff (whole cars) the 3000 clear is real fast. Heat it to 120 or 140deg depending on catalyst for as little as 10min. Yes TEN MINUTES! Cool down and wetsand and rub. No shrinkage or dieback. The 4000 clear is just as good, a little more time to heat cure, better gloss and flowout and a great choice for OAs. The nice thing about DBC is the consistancy of solvent use. DBUs reactive reducer has been historically "aggressive" and tends to work it's way down deep and mess with bodywork and substrates. DBC has a 24hr re-coat w/out sanding window as well. Here's a link to cruise through. I hope some of this was helpful. http://www.ppg.com/cr-refinish/phase1/frmProductInfo.asp?Cat=21
Hi Group. I hope you dont mind me bumping a 4 year old thread, but in case the people of this thread are still active users, I wanted to say "thank you!". I recently have had MAJOR issues with DBC9700 over K36, and had a very costly repaint. But I noticed it in other places as well, and was really freaking out. I noticed, as stated by Raffman, that it was ONLY in the areas of black. I asked a PPG rep if it was possible that the batch of DMD1683 (same as DBC9700) was bad or not adhering for some reason. He said 'No'. So Ill have to p*** this info along to him. Its kind of a shame because I had just in recent years refined my process to eliminate sealer, Thuis the reason I had never had the problem before despite having used 9700 for 15 years or more. Anyway, Thanks for this great forum, and information. Googling sealers is how I found this thread. A lifesaver.
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