[buckeyedemon]

I used to think it was direct to metal but I was told by the paint supply store that is is not direct to metal unless it is sand blasted. Since they are not open I am unable to call them to have them claify why. I have the p-sheet at home and that was why I thought the same as you. I am sure there is a reason why they told me that.

Whether he is right or not I am uncertain, but there is an addendum on the p-sheet with info. mentioning DX1791/1792. As for the K36, yes, there are some DTM urethanes, but most urethanes (from my experience) are not.

i recommend simply reading the datasheet (if available...).

the P-sheet states the compatible surfaces. the mention of DX1791/1792 is in the DPLF datasheet linked.

you previously wrote "NO" (in capital letters) urethane primer will adhere directly to metal, so i guess i incorrectly interpreted that as none instead of most which is the reason for pointing out the K36 P-sheet. my mistake:shrug:

 

[cmefly]

Thanks for all the great information. I am sure glad I made the post, and didn't go straight to my local store without thinking the process through. Since I have been considering Eastwood products, I went back to their website to check the urethane primer. It says "Eastwood’s high-build 2K Urethane primer surfacer is a dream to blocksand, powdering easily after a short cure time. Use over Eastwood Epoxy Primer. Alternatively, used in conjunction with an etching acid pre-treatment, this 2K Urethane Primer may even be applied over bare metal". This pretty well agrees with the advice I have received so far on this post. I plan to call the tech people at Eastwood to make a final choice.​

I was wondering if there is any difference for priming the interior versus the exterior. But since I have seen no comments on this, I assume that there is no difference.​

One other point - someone said they assume that I am from Phoenix. No, I am from Annapolis MD. My user name relates to the car (hopefully) rising again from the ashes!​

Going by the p-sheet is sounds like the urethane is recommended be used with their etch primer for bare metal adhesion. My preference is to use the same product line as much as possible to prevent problems and resulting disclaimers that you did not use our products throughout the process (minus the paint portion as sometimes you have to use a different paint to get the color you want). I would ask for recommended flash times for the temp. you are expecting to spray at to give you a better idea, as flash times are calculated a 70'. I also would wait to sand it for longer than recommended (I know you were planning on waiting anyways, but you never know how it goes). It will shrink back and waiting (at least a couple weeks depending on temp.) will allow it to do that before you have sanded it. I've seen a lot of cars where the primer has shrunk back after being sanded and as a result there are sand scratches in the paint. Just my $.02.

 

[cmefly]

i recommend simply reading the datasheet (if available...).

the P-sheet states the compatible surfaces. the mention of DX1791/1792 is in the DPLF datasheet linked.

you previously wrote "NO" (in capital letters) urethane primer will adhere directly to metal, so i guess i incorrectly interpreted that as none instead of most which is the reason for pointing out the K36 P-sheet. my mistake:shrug:

I had forgotten K36 since I don't use it, and in trying to remember any urethane that was direct to metal, couldn't come up with any. Hence the "NO". It certainly isn't common in urethanes which is why I use acid etch and recommend it. You also left out the "...it is my understanding.." before the "NO" which seems a bit dishonest of you as it changes the meaning of the sentence. It implies that I am not aware of any that are DTM urethanes. Not the definitive statement "there are "NO" urethanes that are DTM". I'm not quite sure what the last statment is saying and so don't know how to reply. I will call the paint shop tomorrow and find out the reason for the recommendation about DP90 if only for my own edification.

 

[snowmanhat]

epoxy primer for sure

 

[palerider]

Epoxy SPI - just shoot it and leave it on. that what I did with mine and then took to body shop and they used the high build etc. Neded to check on bondo work you did - I know is recommneded filler over epxoy not sure about shooting epoxy over filler though.

 

[buckeyedemon]

I had forgotten K36 since I don't use it, and in trying to remember any urethane that was direct to metal, couldn't come up with any. Hence the "NO". It certainly isn't common in urethanes which is why I use acid etch and recommend it. You also left out the "...it is my understanding.." before the "NO" which seems a bit dishonest of you as it changes the meaning of the sentence. It implies that I am not aware of any that are DTM urethanes. Not the definitive statement "there are "NO" urethanes that are DTM". I'm not quite sure what the last statment is saying and so don't know how to reply. I will call the paint shop tomorrow and find out the reason for the recommendation about DP90 if only for my own edification.

I'm dishonest because I left out "...it is my understanding.."?

I don't agree with that. I quoted that part of your statement in my response about 10 posts back. Notice, I haven't edited that response to add in "it is my understanding".

I'm only trying to correct possible misleading or wrong information so others don't go on repeating it.

Just for reference, PPG offers some other primers that can be applied directly to metal besides K36.


DPLV

DPS

NCP


some others in the "K" family

K38

K93

K200

 

[montana]

This has been a really useful thread and I know I'll refer back to it when I'm ready to start my bodywork and need to prime.

 

[andrewdrexler]

You don't really have to sand epoxy, just reshoot in the window. After the window has expired you just scuff it, then shoot. It is expensive, but IMHO I want the best rust protection money can buy.

+3. I sprayed Kirker 2 part Epoxy on my engine compartment and missed the re-spray window of 4 days due to bad weather. Once things had cleared up, I scuffed with 180 and sprayed another coat of Epoxy and then hit the re-spray windows for color and clear.

 

[Woodchuck]

I use polyester high-build over my EP. Text below from autobodystore.com. Yeah, it IS somewhat a beetch to sand, but I think the effort is well worth it.

Polyester is a very specialized primer used in very small amount in most shops across the country. But when it is needed, it does a job like no other. Polyester has a huge solids content and will fill 80 grit scratches in one coat or 36 grit in two or three! Urethane for instance provides about ½ or ¾ mils per coat while polyester can give you as much as 4 to 6! Because of it’s high solids, it shrinks very little. It is basically like spraying polyester putty. Look for a manufacture that has a recommendation to apply etch primer under it. I see NO reason to use polyester on a straight panel. It is for use only when you need some serious filling and surfacing.

Benefits:

- VERY high filling

- Low cost

Disadvantages:

- Very high texture

- Harder to sand than a urethane

- Possible need to purchase a large gun to shoot it.