Paint and undercoating prep after sand blasting

[HaZmatt]

I am getting my car back from media blasting next week and wanting to know what I need to do to prep the car before paint. Here was my plan;

Interior floor pans:

Weldable primer around areas to be repaired

Epoxy primer

Seam sealer

Rustoleum paint

Sound deadening material

Undercarriage:

Epoxy primer

3M undercoating

Exterior/Engine bay:

Epoxy Primer

The rest will be done by body shop prior to paint

Am I on the right track? Should I paint the undercarriage before I lay down the undercoating? Thanks for any input.

[black gold man]

Weldable primer is for inside areas that cant be reached after the welding is done.

[HaZmatt]

Weldable primer is for inside areas that cant be reached after the welding is done.

Yes. I was referring to my floor pans that I will be overlapping and welding.

[Jason240z]

Yes. I was referring to my floor pans that I will be overlapping and welding.

why are you lap welding? that's asking for trouble.

[grannyknot]

HaZmatt,

I would use weldable primer around anywhere that needs patching /repairing and epoxy primer on everything else.

Weldable primer can actually be welded through, that is the only reason to spray it, once the repairs are done apply epoxy primer.

I would apply paint on top of any primer before undercoating, even if it is only rattle can paint. I have had to completely redo the bottom of a TR6 because I sprayed undercoating over bare primer. It may not happen to you but I'm just saying. If water gets past the undercoating then the primer won't protect anything. The job of primer is to give "tooth" for paint which does the job of sealing.

Rustoleum works fine on the interior but it does take a l o n g time to cure.

Make things as easy as possible for the paint shop, it will cost you less and you will get a better job in the end.

Jason, I would agree that generally a lap joint is a bad idea but as these cars are going to be treated very well from now on after a resto I can't see anything wrong as long as both pcs are well sealed before and after welding them together.

[HaZmatt]

Thanks for the info grannyknot, thats what I was thinking

[ksechler]

Be careful with the weldable primer. It isn't as weldable as bare metal. You will get a lot more spatter and it's harder to get the initial bead (when you strike the weld) to penetrate. I'm not sure what Jason's issue with lap welding is. When replacing floors you would find the fitment for seam welding almost impossible. I lap, plug and seam welded my floor pans in.

[HaZmatt]

Be careful with the weldable primer. It isn't as weldable as bare metal. You will get a lot more spatter and it's harder to get the initial bead (when you strike the weld) to penetrate. I'm not sure what Jason's issue with lap welding is. When replacing floors you would find the fitment for seam welding almost impossible. I lap, plug and seam welded my floor pans in.

Good to know. I havent welded in like 15 years so I will need a little practice. Maybe turning up the welder a little more when going through the primer? I will test it out on some scrap metal first.

Im not sure whats wrong with lap welding floor pans in either. I always thought that was the correct way to do it, as long as you use weldable primer and seam sealer i dont see any issues. But to each his own.

[bartsscooterservice]

zinkspray ?

[ksechler]

Good to know. I havent welded in like 15 years so I will need a little practice. Maybe turning up the welder a little more when going through the primer? I will test it out on some scrap metal first.

Im not sure whats wrong with lap welding floor pans in either. I always thought that was the correct way to do it, as long as you use weldable primer and seam sealer i dont see any issues. But to each his own.

Yes, actually I think you hit the nail on the head. A little more amperage seems to be the trick when using the weldable primer. I tried that today and had very good results.

[Dr. 240Z]

I am getting my car back from media blasting next week and wanting to know what I need to do to prep the car before paint. Here was my plan;

Interior floor pans:

Weldable primer around areas to be repaired

Epoxy primer

Seam sealer

Rustoleum paint

Sound deadening material

Undercarriage:

Epoxy primer

3M undercoating

Exterior/Engine bay:

Epoxy Primer

The rest will be done by body shop prior to paint

Am I on the right track? Should I paint the undercarriage before I lay down the undercoating? Thanks for any input.

HI,

While you are at it and have the access opportunity, I suggest that you consider spraying the internals of the frame rails with Eastwood's specific product or something similar.

[Oiluj]

Do you really want to undercoat? Mine has undercoat and I'd prefer it didn't.

A clean, painted underbody let's you see corrosion, where undercoating can hide it till it becomes a bigger problem.