2K Primer questions and clarifications

[tradercj]

Just making sure I got this right

Over bare metal I am putting epoxy primer. If the epoxy sits for a few weeks, I need to sand it, the apply epoxy then the 2K.

If you do not add a reducer to the 2K, then it is a considered a filler. Then you block and sand. After this do you spray 2K then bc/cc or do you have to spray epoxy again? When you spray 2K before bc/cc that is when you add a reducer, called high build?

If you sand through the 2K, going down to the epoxy or bare metal, what do you spray then before the bc/cc. Epoxy or 2K?

Is it better to spray just epoxy or epoxy and 2k if the parts are going to sit for a while?

I think I confused myself more just writing this! Thanks in advance, Chris

[frostje]

Just making sure I got this right

Over bare metal I am putting epoxy primer. If the epoxy sits for a few weeks, I need to sand it, the apply epoxy then the 2K.

If you do not add a reducer to the 2K, then it is a considered a filler. Then you block and sand. After this do you spray 2K then bc/cc or do you have to spray epoxy again? When you spray 2K before bc/cc that is when you add a reducer, called high build?

If you sand through the 2K, going down to the epoxy or bare metal, what do you spray then before the bc/cc. Epoxy or 2K?

Is it better to spray just epoxy or epoxy and 2k if the parts are going to sit for a while?

I think I confused myself more just writing this! Thanks in advance, Chris

I might be able to answer some questions here. After you spray it intitially and cover it with bc/cc, you only need to scuff and shoot to reapply any color. As far as direct to metal primers only 2 are applicable, epoxy and etch. Primer surfacer and sealers are more to use as a block coat to apply for possible reaction problems, also high build is made to cover imperfections in your bodywork, it is probably a last resort since your bodywork should have been blocked flat to begin with. If you sand through you have to recoat with epoxy before you shoot. Paint will not adhere to bare metal, period. there are 1k and 2k products for primers, 1k have no harderner/reducer in them and are usually sealers or spray bomb junk, or Ive seen some napa crossfire 1k laquer primers. Not very good. Always use a 2k product and you never go wrong.

[JCCLARK]

Over bare metal I am putting epoxy primer. If the epoxy sits for a few weeks, I need to sand it, the apply epoxy then the 2K.

Once sanded, you can put anything over epoxy, like 2K primer, paint, etc.
You don't need epoxy a second time.

[JCCLARK]

Most 2K primers are high build, some more than others,
adding reducer to them only thins them
to make them spray better and/or lay smoother.
With or without the reducer the 2K is the same product.
The reducer evaporates and adds nothing.
Adding reducer will make you need more coats to get the same "build".

[Len]

Just making sure I got this right

Over bare metal I am putting epoxy primer. If the epoxy sits for a few weeks, I need to sand it, the apply epoxy then the 2K.

If you go out of the "recoat window" you can usually just sand the epoxy and apply your 2K primer.

If you do not add a reducer to the 2K, then it is a considered a filler. Then you block and sand. After this do you spray 2K then bc/cc or do you have to spray epoxy again? When you spray 2K before bc/cc that is when you add a reducer, called high build?

If you do not add reducer the 2K may be too thick to spray. Read the technical info for the products you're using.

If you sand through the 2K, going down to the epoxy or bare metal, what do you spray then before the bc/cc. Epoxy or 2K?

If you're just down to the epoxy you may be able to just spray your base but if you hit metal you should apply more epoxy. Again, read the technical info from the primer manufacturer.

Is it better to spray just epoxy or epoxy and 2k if the parts are going to sit for a while?

I like spraying the epoxy AND the 2K because it saves a lot of work when you don't need to sand if you're within the recoat window.

[tradercj]

Thanks for the great quick replies.

One more question,

after you sand the 2K primer, do you apply 2K primer then the bc/cc, or can you apply the bc/cc over sanded 2K primer.

[another2centsworth]

apply your base over the sanded primer.

[JCCLARK]

check the tech sheet for your primer,
Every 2K primer I've used says it has to be sanded before painting over.

[Len]

Thanks for the great quick replies.

One more question,

after you sand the 2K primer, do you apply 2K primer then the bc/cc, or can you apply the bc/cc over sanded 2K primer.

You should sand the 2K with 400 or 600 grit wet paper then apply your sealer or color.

[MARTINSR]

The one thing I would like to add to this discussion is a pet peeve of mine that I will never be able to change so I shouldn't waste your time but "2K" covers a LOT of ground, the EPOXY is a "2K"! If we call the products by their proper names then we can understand their uses and such a lot more.

Here is a "Basics of Basics" on paint technology that can be of a lot of help. http://www.autobodystore.com/ms7.shtml

Brian

ps Now I need to work on people using the word "Fitment" as an adjective or verb as in the "Fitment of the fender" when it's a noun, it's a piece of furniture, a couch basically, in Europe! That one drives me nuts!

[another2centsworth]

Brian I understand your peeve. I have come to the conclusion that it is a losing game. You would be correcting all day.

[Len]

Brian I understand your peeve. I have come to the conclusion that it is a losing game. You would be correcting all day.

Maybe we should start calling the different primers "DTM" or "filler" primer instead of epoxy and 2K.

[JCCLARK]

Brian I understand your peeve. I have come to the conclusion that it is a losing game. You would be correcting all day.

I agree with that!!!!!

[MARTINSR]

I don't think there is anything we can do honestly, all I know is the proper name helps with a proper understanding of that they do and how to use them.

Chris, please don't take my comments personal. I didn't mean to sound like YOU did something wrong. The use of "2K" in describing a urethane surfacing primer is so common if anyone hung out on any autobody forum on the net for more than a day it's what they are going to learn. It just bugs me as it doesn't help anyone learn if there is this blanket name for very specific product.


Brian

[tradercj]

Brian,

I did not take any offense. I agree using the proper terminology makes it less confusing for everyone.

Chris