The Stovebolt Site Forums The Shop Area Paint and Body Shop Tips on DP primer as a sealer

I am finishing a long term project and am getting close to color (PPG concept solid).

The car started out with a good coat of DP-90 on it. Body filler, fill primer to final guide coat.

I am not getting ready to seal the car using DP50 (now LF). I mixed it using the instructions on the can (2:1) and added a little 885 thinner. Probably over the limit on what the sheet says you can thin it to.

Is sprayed pretty decent but I guide coated using 3m dry guide coat with 800 and there was more orange peel than I care to sand.

I am using a Devilbiss GTi gun and all I have are the stock fluid tips (1.6 and 1.8).

I would like to flatten this out a little more if possible. Any comments on tips, thinning??

Thanks in advance,

Rich

Personally do not like dplf when used as sealer. I dont like it for a few reasons.
#1 as you found it orange peels
#2 It sands like half dried glue
#3 When dplf is used as a sealer then topcoated directly over it has a nasty habit of dieback. Meaning the topcoat loses gloss.
The only way Ive found to prevent this is to spray the DPLF sealer allow it to sit and cure for a few days. Then come back 2-3 days later sand and paint. This allows the epoxy some time to cure. The epoxy when topcoated directly tends to suck up the solvents in the topcoat later releashing them, thus the reason for dieback.

A 1.4 tip would be a better choice for spraying the DPLF. The 1.4 will break it up better leaving behind a smoother finish.
800 grit seems a tad too light for me. I would step up to 500 grit.
DCC has no problems covering up 500 grit scratches. Plus 500 grit will level that surface faster and better then 800...Eric

Thanks for the response.

I have not shot concept before so was not sure what I could get away with as far as sand scratches so thought 800 was safe. The fill primer underneath is pretty much "leveled" and this is a final sealer only.

As far as time, thats not an issue. I am paranoid about that and because of defects I have seen from people rushing primers I wont even sand primer once I get to the guidecoat stage until it has sat for two days. Probably stupid but I dont want to have any shrinkage. I have plenty to do on this frame off 67 Z so a couple days is nothing

The reason I ended up with DP for a sealer was my jobber talked me into it. Originally I had a mix of DP and K36 Kondar on the car and was planning on sealing both of them. As it turned out I shot K36 on everything and did one final guidecoat as I have had problems with DP lifting DP anywhere there I had sanded through to bare metal. So I could have used any sealer as it turns out.

I am not expert at all, but I personally like how DP sands once cured. Just not for the first day.

Rich

PS: Nice to see another GM musclecar guy on here.

Here is a couple pics of "project"

[img]http://www.ctiowa.com/z-bottom.jpg[/img]
[img]http://www.ctiowa.com/z-inside.jpg[/img]

Rich,
if you wait 2-3 days you wont have the dieback issues with DPLF. It happens when you topcoat right away, I believe the numbers are 30-60 mins depending on which hardner used.

DPLF when used as a sealer is a good sealer when doing resto work as you have all the time you want. I just dont care for it because I do production collision repair and I dont have the needed time it takes to make epoxy work...Eric

I have had bad luck with dp90 and will never use it again. why is it that we can send a man to the moon but we cant make paint stick. I hate paint.

Am not a huge fan of DPLF either, but reading your other post I wonder what hardner you used with NCP271? DPLF402 is the ONLY hardner that can be used in DP when NCP is applied over it.

I to once used Dp as a sealer, but now use Chromatic sealer by PPG Global and love it! Dp is good for bare metal and that's where it ends with me!

I am using DFLF402 now, but the stuff under the NCP is actually DP90 (before the LF). I dont remmeber the number but the hardener I used with the first DP was the stuff you had to let activate for 30 minutes.

I really have not had any problems with DP with the exception of it lifting feather edged DP.

At this point I am not sure what I think about it as a sealer. I ordered a 1.2 tip for my gun and going to see how that shoots. Once cured and sanded it looks awesome.

The biggest thing I like about DP is putting it on bare metal and filler over it. Really seems to bite.


Rich

DP 401 would've been the stuff you used if you had to let it sit for 30min. DP with 401 you can let sit in your gun for 3 days. I believe either way (401 or 402) you have to sand if you don't top coat within a week. DP LF sucks compared to the old straight DP. (IMO)

Yes, I did sand before topcoating.

And I agree on the LF. I am very disappointed in it compared to old DP. I used to paint chassis parts with DP and leave it. Was the perfect gloss and durable. I wont be doing that anymore with LF.

Rich