I've used different manufacturers of primers and paints and have never had a problem. I'm not saying it can't happen, I'm just stating I do it. Some day I may get bit in the a** by doing it but so far I haven't had any problems.

I don't mix different manufacturers components of paints like hardeners and reducers for automotive paint. I do however use the Valspar hardener in different brands of off the shelf common oil based paints like S-W and even Rustoleum, if my customers spec a Rustoleum color, without any trouble.

 

Good tips, but i still cannot get anyone to really recommend a specific primer brand name and type. I guess its because there so much out there. Right now i have the truck sprayed in white rust oleum primer, and i am just not sure where to go with it. Should i sand all of the primer off or just take it down a notch before i paint with a higher quality primer or what?

 

If you can, I would strip the Rustoleum primer completely off and then apply a good quality epoxy primer. If you apply the epoxy primer over the Rustoleum you will not be able to have the adhesion of the epoxy primer, you will still only have the Rustoleum primer's adhesion. Also, again, if you apply the stronger epoxy over the Rustoleum you may lift the Rustoleum primer, then you will have to strip it to bare metal, a real mess.

Find a good automotive paint store in your area and buy the epoxy primer there. I buy mine from NAPA, it hasn't failed me yet.
This stuff might seem elementary but you sound like you have very little experience with paint and none with automotive paint and I want to make sure your realize the dangers of working with this stuff. I found out the hard way a couple of days after starting my first job in a body shop. I thought the shop was cleared out and my boss even removed his respirator so I thought it was safe for me to do the same. By night time I could hardly breath and I was coughing up blood. Not a very nice experience.

 

I'll get the product # off the cans for the SW primer and post it later today. This primer is also iso free, an important feature to me since I don't have a paint booth.

Iso = isocyanates, the active ingredient in superglues, and a common component of epoxy paints to give adhesion and hardness. It sets up in the presence of moisture, so if you breathe the fumes without proper breathing aparatus it will harden in the lungs. All that can be done once this happens is to watch you die, there is no way to reverse the effects.
Iso free doesn't mean it's safe to breathe, it's still paint and solvents, but you won't need a supplied fresh air mask just a solvent vapor mask if you have ventilation.
Be sure when buying any paint, especially one that has a hardener that needs to be mixed with it that you ask for and read the manufacturers product safety data sheet before purchasing. Every chemical sold for industrial use is required to have one. This is one place you don't want to try to save money or cut corners, we don't want this hobby to kill you.

 

BobJ, I got bit using one brand base coat and another brand clear coat on a small repaint. That is, if you can call half a door, small.

Remember in the old days you couldn't paint lacquer over enamel? You can if the enamel has a hardener in it.

 

I can't get Uro anymore

I love that stuff too. Bare metal, still holds up great.

 

I wouldn't mix base coat/clear coat products from different manufactures but I have used primer from one company and a top coat from another without a problem. I just might have been lucky so I wouldn't encourage anyone to to do it.

The modern urathanes can take almost anything once they're cured. Even using the Valspar hardener in hardware store paint makes a difference. On my 8N tractor I sprayed the entire tractor using Valspar paint with hardener but I forgot the oil cannister. I didn't want to mix up a small batch of paint just for the canister so I used a spray bomb can of matching Valspar paint to paint the cannister. After I had the tractor together and running some gas dripped from a bad valve under the gas tank. The hardened paint wasn't affected but the paint on the cannister peeled. I wish I had done the extra work and mixed a small amount of paint for the cannister.

 

Bob, I had run out of same brand clear coat, so being smart I grabbed what was handy. Handy doesn't mean it'll work. I didn't.
I've also mixed primer from one manufacturer with a base coat or even single coat paint from another manufacturer with good results, but most paint shops say stick with the same bran all the way thru.

 

That's mainly due to suppliers and its easier that way. I work in a body shop and have used different primers, bases, and clears on a car one time or another. Used DuPont base with Sikkens clear, Lesonal base with DuPont clear, DuPont base with Montana clear (their Euro clear is a nice product), Utec base and clear with DuPont products, etc.

Never had one problem doing it that way. If you prep the parts correctly and mix the paints correctly their shouldn't be a problem.

 

Deebee, since you work in a body shop I have a question. My paint is around 8 or 9 yrs old and I want to color sand and buff it again. Should I de-wax it 1st or does it matter?
Also, when I reshot that door the clear coat crazed like smacking a mirror with a hammer. That's what happened to me (it's in the clear 'cause you can feel it).

 

DeeBee I thought I had read where they were coming out with something new. I love the 1120S and I have about a half gallon left and then it is on to the new stuff. The new stuff is supposed to work the same way but be a 2 part mix instead of a 3 part mix, sometimes I hate change.

DeeBee or anyone can correct me or add if you have a better way but.... f100kid you can color sand it if you are careful. I will tell you after sitting this long it is going to be alot of work because the paint gets harder with time, it may not be bad sanding but sometimes it can be a bear to buff all the scratches out. The cracking on your door needs to be taken all the way down and repainted or it will keep doing the same thing and I don't think you will ever buff it out.

Codys50, it is hard for anyone to tell you what to use exactly. I love Dupont and try to stick with it all the way through plus if something goes wrong I have an area rep that will comp me paint if it is all Dupont underneath, I like that kind of service. The next person might like PPG and the next RM, or Sikkens or..... well you get the point. Alot of it is what a person gets comfortable spraying. Generally your better name paints will give you the least trouble if you use them according to the directions. They didn't get that way with alot of bad materials. I would like to tell you go use "this" but I don't know your experience, I would reccomend talking to some local body shops and see if you might be able to ask them some ?s. Just remeber time is money and they might be too busy to talk right when you show up.

 

I sprayed my 56 cab today with omni base-coat and did it in the drive with a hvlp sata gun and 5 h.p. and 33 gallon compressor...The white canopy over top worked great. I suggest all 1st time painters to try base coat and omni is 65.00 for 2 quarts of color and 2 quarts reducer.....Then you clear it. I now will set it on the frame this week,after it sets up nice. I will go to ksmith's tomorrow and load up the 272 yblock and 4 speed for my f100 truck. Then go with him to pick up his new 66 ford wrecker. I have to keep busy so ksmith doesn't blow my doors off and finish his truck before me this year. Anyway---omni base coat is nice to use and cheap....Bill

 

I have decided to go with Du Pont Variprime 615S & 616S. Then with their urethane primer over that.

R

 

The new stuff is not anywhere close to Uro. You should call your supplier and see if they have any left on the shelf. We got lucky and picked up a couple extra quarts.


I would avoid color sanding old paint. For one, there is a good chance you will spend days and days trying to get the scatches out (ask me how I know, haha) and two its easy to sand throught the clear since you don't know how much is on there. Try using the compund on a high speed buffer without sanding.

That door with the shattered clear, definitely needs to be stripped and start over.

 

thanks everyone, without you guys help i would have been completely lost in the paint department. I ended up purchasing a eurothane primer made by transpar i believe it is. I was told by carquest paint it was a good choice, atleast i know it wont shrink like the rustoleum so ill go with it.

I am attempting to get all the old rustoleum off...to prep to prime with the real primer now.

I wanted to ask a few safety questions about this stuff. Ive always used a respirator when sanding and all that stuff. It is a dual intake kind (for lack of the proper word) it wasnt purchased from a paint shop but i think it is sufficient. I just want to be safe with this paint and i am curious first off if i have the proper respirator and when is a safe time to enter without a mask after painting?

I dont want to ask a million questions but i trust yalls info and i want to be safe with this stuff. Thanks for the help