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Sun Jan 10, 2016 4:56 pm

I am ready to lay on some k 36, and I read the P sheet which says use a 1.4 to 1.6 tip.

From everything I have read primer surfacers are quite thick and require a 1.8 to 2.0 tip.

I have a Harbor Freight gun and it only comes with a 1.4 or 1.8 tip. I thought I was ready.

Has anyone shot K36 with a 1.4 tip, or can I go with my 1.8? Is this stuff that thin?

Sun Jan 10, 2016 5:12 pm

Do yourself a favor and return that K36. Its more of a finish primer and it really is too thin to work well. Ive had countless problems with that stuff shrinking and showing sand scratches through it. I would never use it again. K38 is much better in my oppinion.
But to be honest, anymore, I really prefer using a poly primer to start. Something like "Evercoat Slick Sand". It has much much more build, never shrinks, and really locks down any filler work you have. What I do is use a poly primer (2-3 coats), block it down to 180 grit, then spray a 2k primer on it (like K38). Then you can wetsand that and paint.
Poly primer really needs a big tip to spray though. You could make do with a 1.8 tip, but that forces you to thin it and takes a little away from the high build property. A 2.0 - 2.5 tip is much better for spraying that stuff. It really works amazing though. Fills all the pinholes you have in the filler and even is thick enough to fill some slight low spots.

Sun Jan 10, 2016 6:18 pm

I like the idea of Slick Sand because of the high build and less toxicity (I thought k36 was high build) however everyone says to stay with one system.

I am not able to use the chemical bond properties of these systems, since I am too slow. So I have to rely on mechanical bond for every step. Primer guns are cheap so if I use Slick Sand and then use the k36 (with tint) as a sealer ( in case I can't return it) will this cause any problems?

By the way my primer coat is PPG DPLF

Sun Jan 10, 2016 7:49 pm

It wont cause any problems at all. Evercoat and PPG play well together. But I would still try to take that K36 back. If you have any of that DPLF epoxy left I belive it can be reduced and used as a sealer. If I remember right it even has a window of one week before it would need scuffed to paint over. Anything before that should really be sanded anyway. The more you block it, the straighter it will be.

Also you really dont need a sealer. I assume you are using PPG paint too? Hit it with your Slick Sand (3 coats), guide coat it, sand it with 120, guide coat it again, and then sand again with 180. Shoot a 2k primer over that (2-3 coats). If you are satisfied with the work you have done, you can go right to 400 wet and be done with it. If your unsure, go over your 2k primer with 220 dry just to be sure. Then guide coat it again, and go over it with 400 wet. She will be ready for paint after that.
Unless you already have it, sealer is just another step and added cost. Most modern paints will cover that just fine without sealer. If you have extra time and money, then go ahead with the sealer, if not, skip it.

Sun Jan 10, 2016 8:04 pm

I should also point out that if you spray your 2-3 coats of slick sand on and after you sand it, its not as straight as you want, dont be afraid to hit it with 2-3 more coats. By then you will have sanded most of the first session off anyway. Ive done it plenty of times. Slick sand is relativly cheap so dont be afraid to use it. The body work is the hard part and not where you want to rush.

Also if you have pleny of slick sand left on it after you sand it with 180, you can finish that stuff with 400 wet and paint right on top of it. I usually dont just because its easier to spray a couple coats of 2k over it than it is to work the 180 down to 400. That said, I have painted a couple dozen cars right on the slick sand with no problem at all.

Mon Jan 11, 2016 10:30 am

Ok I'm going to go with Slick Sand.

When you say cover it with a 2k primer are you talking about something like DPLF? I am not excited about sanding this, as it loads up the paper.

Why a 2k primer instead of a sealer? If I sanded the Slick Sand to 400, I could just apply a sealer. I am out of DPLF so I would have to buy something anyway.

I'm heading out now to try and return the K36.

Mon Jan 11, 2016 12:08 pm

No not dplf. Something like k38 . And if you sand the slick sand to 400, sealer would be fine. It would be easier to sand the Slick Sand to 180 then spray k38, then sand that with 400. Slick Sand doesnt sand real easy. That's why I would spray k38 over it once you have it to 180. But you certainly can sand the slick sand to 400 if you want.
And yeah, dplf sucks to sand. Maybe try some SPI epoxy next time. Its cheap, works well, and is more sandable. I did the same thing as you on my first paint job and that dplf shit was a pain to sand.

Mon Jan 11, 2016 4:36 pm

It seems I should have kept the k36. From what I've read it has similar properties to k38 and it tintable, k38 is not. I had the blue tint already.

I intend to use Omni SS paint since Omni and Delstar are the only 2 PPG products that can be mixed in L360 Sea Blue.

Tue Jan 12, 2016 5:00 am

Well you could always go back. From my experience, I would never use that stuff again though. Google k36 and see what others think of it, but I'm betting you find more of the same I had.

Tue Jan 19, 2016 1:26 pm

uffdakev wrote: It seems I should have kept the k36. From what I've read it has similar properties to k38 and it tintable, k38 is not. I had the blue tint already.

I intend to use Omni SS paint since Omni and Delstar are the only 2 PPG products that can be mixed in L360 Sea Blue.

Get a small amount of the Omni and spray it out on a piece of metal, smooth cardboard or something like that. Then take the dried sample to your paint supplier and have them read the color, so they can mix in Concept. I did that with my 64 T-34, and it worked out great. I've also had them convert the Omni color to Deltron (BC-CC) as well, doing the same thing. My 64 T-34 was painted in Concept, mixed to L360 Sea Blue #2 color.

Ideally, you want to seal the slick sand with some DPLF, mixed up to 10% with some DT870 reducer, to turn the DP into a primer sealer before you paint. This is how I do it on a bunch of vehicles. I use and like PPG products, especially their primers/primer sealers, with DP being 1 of my favorites. Keep in mind that the DP is not a sandable primer, and even if you have to sand it, you should wet sand it, flushing it often with clean water (both the paper and the vehicle).

I prefer to stay away from the Omni paint, as it's really not that great at holding it's color. BTDT a few times, and had to redo the job.
I hope this helps.

Wed Jan 20, 2016 4:45 pm

Thanks Bobnotch,
I will look into this. Do you have a mix number for Concept Sea Blue?

I didn't have much luck with the DPLF without reducer. It orange peeled pretty good, and that appears to be a common problem from people on this forum. Is this my inexperienced technique or is that the nature of the beast, unreduced?

Wed Jan 27, 2016 12:12 pm

uffdakev wrote: Thanks Bobnotch,
I will look into this. Do you have a mix number for Concept Sea Blue?

I didn't have much luck with the DPLF without reducer. It orange peeled pretty good, and that appears to be a common problem from people on this forum. Is this my inexperienced technique or is that the nature of the beast, unreduced?

No number, as it was a "custom mix". They did a spray out card for it though, so I could get more IF needed. Then they changed paint suppliers (going to Dupont), and they had to mix it in a different formula. :roll: They closed up about a year later, and now I either have it done 35 miles away (for PPG) or locally for Dupont. It really sucks, as I'd been using them for over 20 years.

Yes, DPLF will go on with an orange peel like surface if you don't reduce it. I actually use a touch up gun (siphon feed) when spraying it, as it doesn't orange peel as much. However, most people are putting it on bare metal, then adding a primer surfacer (sandable primer) over it an hour later. After sanding the primer surfacer, you can shoot more DP on, then either wet sand the DP (with 320), or add the reducer to it right before spraying paint. I do both, as I like a smooth surface for painting, but also want some mechanical grip from the epoxy.

Wed Jan 27, 2016 12:21 pm

I should also mention that you have a "working" time window with the DP. It's anywhere from 1 hour after shooting, to 7 days after shooting. I normally wet sand after 3 days if used full strength (no reducer added). After 7 days, you have to scuff the entire area and re-apply the DP before any other work can be done. So keep that in mind when using it.

Wed Jan 27, 2016 10:26 pm

Ive personally never been a big fan of DP. It works great...its just hard to work with. Ive never liked the way it sands. In my oppinion, SPI epoxy is a much more user friendly product, and its a third of the price.

Also there are many ways to skin a cat, but for me, most catylized primers are just fine for painting over.....sealer or not. If I use a sealer, I just get sealer, not a reduced epoxy. I also prefer to paint over a sanded surface, which is why I usually dont use a sealer. Using a sealer does seem to use a bit less paint, but the sealer is just as expensive as paint, so its just not worth it for me. When I do use a sealer, it is dry quick enough I can nib it if I get something in it, and move it right to paint.

Bob do you wetsand your primer before applying the DP?

Wed Jan 27, 2016 10:42 pm

buguy wrote: Ive personally never been a big fan of DP. It works great...its just hard to work with. Ive never liked the way it sands.

Bob do you wetsand your primer before applying the DP?

I do agree it can be a PITA to sand, but once you get the hang of what you can and can't do with it, it's fine. I've been working with it since 1990. This was before they took the lead of out it (the LF stands for Lead Free). It was a very good product before it became LF, but you work with what you got.

I don't wet sand primer surfacer, but I do wax and grease remover it a few times to get the surface clean, clean, clean. Then I reduce the DP, and shoot it. A half hour later it's ready to be painted. I've found using the DP as a sealer works very well for metalic paints, as you don't get zebra stripes, but it also allows you to get better color flow as well (solid colors). Add in that almost every VW I've ever worked on (with OE paint), they've all had a white base put on them under the painted color. Using DP48 (white) replicates that, if you're doing a stock VW color. :wink:

Wed Jan 27, 2016 11:01 pm

Ok that makes more sense that you wetsand the epoxy if you dont wetsand the primer. Although you really could use about anything you wanted as a final primer. But I do agree that DP would be great if your going to use it as a sealer and go right to paint. I always seem to get trash in it (not the greatest booth) so I prefer a sanded surface as I go to paint.

Wed Jan 27, 2016 11:20 pm

buguy wrote: Ok that makes more sense that you wetsand the epoxy if you dont wetsand the primer. Although you really could use about anything you wanted as a final primer. But I do agree that DP would be great if your going to use it as a sealer and go right to paint. I always seem to get trash in it (not the greatest booth) so I prefer a sanded surface as I go to paint.

I used to do that, but with some paints and primers (shooting metalic), it seemed that you'd get light and dark spots, and zebra stripes from some of the paint laying better in some spots, than the rest of the panel (or car). It just seemed that I was throwing a lot of paint on a small area. Since going to the sealer (reduced DP), I use about half as much paint, which makes a big difference when shooting red (the most expensive color). I try to help people out where I can, and if I can save them a few bucks along the way, that's cool too. This is especially true when the paint you're shooting is 178 a quart (a metalic red Honda color, that's got a lot of pearl in it). That's just the paint, no reducer, as that's extra. :shock: But the same applies to solid colors as well, as the stuff isn't getting any cheaper.