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wreckedGTI 11-16-2005 10:38 PM

Sealer over 2K primer surfacer, yes or no?
Do you guys usually use sealer over 2K primer surfacer?
I have heard some people swear by it, some others don't bother with
it and claim it's an unnecessary step in the paint process, and to make things even more 'interesting" I have read some people use epoxy primer to seal the job before bc/cc, so what gives now?

Another thing that makes me wonder is in most tech sheets, they don't advise to sand the 2k sealer, but what if I decide to use it, spray it and it doesn't go on as smooth as I would expect it?, I want to be able to sand smooth before the basecoat goes on.

Any help into this matter would be greatly appreciated, Im to the point where I have my 2k primer surfacer as flat as I can get it, or at least it seems that way lol, and now Im almost ready for basecoat.

beemdubya 11-17-2005 12:41 AM

U dont really need a sealer if its going over 2k surfacer unless its a transparent color or something.. but if i break through the 2k i will usually use an epoxy sealer just in case.

OneMoreTime 11-17-2005 12:56 AM

Maybe someone else has a different idea on this but the only reason I can come up with for using a seal coat is if one has been to the wrecking yard and come up with a blue fender a red fender a green hood and a black trunk lid and it is all on orginally a beige car so to speak..

So now there is all these different colors on the car and we need to do something to get a uniform base to apply our base coat to..that is why we would use a seal coat at least to my way of thinking..


Scode68 11-17-2005 05:40 AM

Since the primer-filler Iím using can be used for fill and the mix ratio changed for use as a sealer I get your point. I tend to think that the filler is so you can sand out the imperfection and then the sealer is used to give you a uniform color to base over. I also suspect that since they give you a window where the sealer should be based over that it also acts lick an adhesion promoter. When that window is gone you will have to sand it anyway in order to get the base to adhere properly.

Bee4Me 11-17-2005 06:58 AM

Some of the cheaper 2k's and most of the old 1k primers are bad about sucking up base paint requiring more coats is one reason sealer's came about.
Also allows you the option of tinting for a color closer to the base if the 2K is off some for what you need.
The better 2k's are good to go and most use sealer as "feel good" or just in case their sanding skill's are lacking.
I personally have not used epoxy as a sealer coat so I can't comment on that.

MARTINSR 11-17-2005 08:27 AM

I have not used sealer over completely primed panels in years. If it is a primer spot on a panel, sealer is a good "insurance". If the panel is primed complete, it is a waste of time and money.

I used sealer on every job I did, but haven't now in years.

I stopped after the first trip to a tech school put on by a paint company. Now, the first thing you will hear from the masses is how the paint company just wants to sell products, be damned with if they are needed or not, right?

Well when the subject of sealers came up, he had writen on the board the part numbers of the company sealers and then asked why do we use sealers?

He put a list up on the board as answers, "Too coarse of sand paper used", "Poor hiding colors to be applied", "1K primer was used", and many more. They were ALL related to poor product choice or improper prep work. He then explained how the 2K primer (be it urethane, epoxy or whatever) is insoluable and you just don't need sealer over it.

I haven't used it since.


crashtech 11-17-2005 08:50 AM

I don't like needing to use sealer, it should really only be used to cover up a problem. The only time a guy trying to do a nice job might need sealer is to provide a uniform ground coat for a poor hiding (transparent) color. Lately what I do in that case is get a solid basecoat color that is similar to the poor hiding color and spray a coat or two of that first. This also seems to help metallic control on the following coats.

So, just say no to sealer. 2K primer is an excellent substrate for topcoating with a very few exceptions.

wreckedGTI 11-17-2005 09:42 AM

Thanks for all the replies guys, recently I painted a car in which I had done some bondo work on it, I used Feather Fill G2 for filling and leveling, after blocking that and putting a second coat on, I sanded it smooth with 600 grit, it looked really smooth in fact that I was tempted to apply basecoat over it, which I did. (after checking the tech sheet and reading some helpful info about G2 in here of course), the job turned out to be very good, no problems with base over G2 whatsoever.

I was asking about sealer because this time around its my car the one I will
paint and was wondering if there was any real advantage to using it, if it
would make the finish look better, but if Im careful enough with my prep
work the 2K surfacer will be good to go.

Thanks again =).

MARTINSR 11-17-2005 11:04 AM


Originally Posted by wreckedGTI
"wondering if there was any real advantage to using it, if it would make the finish look better, Thanks again"

The one thing it will do is add texture. There is nothing like painting your base over a smooth sanded surface. The fewer coats, of any of the products, the less texture.


Paintguy 11-17-2005 12:38 PM

I'm another who'll only use a sealer as a last resort. If the prepper has rubbed through to the odd spot of bare metal, or if I'm painting over a 'sensitive' substrate, that might wrinkle.

If it's just a case of getting a uniform colour to spray over, or I'm putting on a colour with low hiding power, then I'll use a coat of base in a similar colour first, rather than sealer.

MARTINSR 11-17-2005 03:35 PM

Using a sealer isn't a bad thing, I made it sound that way. If you need a uniform color over primer spots, it is the best way to go. If you are doing a lot of work like at a collision shop, it is good "insurance" to seal every job.

There are good reasons to use it, but with completely primed panels, it isn't needed.


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