Advice on treating and painting bare metal/welded patches

[Vern]

Hi can I get some advice regarding the preparation and painting when it comes to covering welded panels on a car.

So heres my uno turbo project below with the work I'm undertaking...



So am I correct in saying I should grind all the surface rust down weld over where required, then sand paper with a corse grit or use scotch brite unsure of this? then apply some Zinc 182 building up the layers?

[optimusprime]

When you say 'weld over' do you mean plate over the hole/rusty area, or cut the affected area out and 'let' in new metal?

[Vern]

Aug 19, 2015 20:03:06 GMT optimusprime said:

When you say 'weld over' do you mean plate over the hole/rusty area, or cut the affected area out and 'let' in new metal?

Hi, yes cut out old rusty metal then replace with new.

The process of primering and sealing i require help with

[ejenner]

I usually go the following route:

1. Etch primer first... it eats into the bare metal so bonds well
2. Cover the seams, where appropriate, with seam sealer, keeps the water out of the welded joints. When you apply be sure that you are forming a continuous seal over the weld.
3. Top coat. This can be anything, satin black, body colour... depends on the location of the repair.
4. If the repair is to the chassis then apply some stonechip chassis guard
5. If it is on the chassis then some sort of waxy product like waxoil or similar would be the final layer

[Vern]

Aug 20, 2015 13:57:26 GMT ejenner said:

I usually go the following route:

1. Etch primer first... it eats into the bare metal so bonds well
2. Cover the seams, where appropriate, with seam sealer, keeps the water out of the welded joints. When you apply be sure that you are forming a continuous seal over the weld.
3. Top coat. This can be anything, satin black, body colour... depends on the location of the repair.
4. If the repair is to the chassis then apply some stonechip chassis guard
5. If it is on the chassis then some sort of waxy product like waxoil or similar would be the final layer

Thank you mate, will order some seam sealer up aswell then.

Brush on or the silicone tube stuff?

I take I need to apply a few coats of etch primer rubbing them down between coats?

[steveo3002]

epoxy primer over clean steel is the best you can do

[Vern]

Ok thanks all for the advice ive ordered a few bits today, this is intended process below..

1. Grind back rust with wire wheel on drill

2. Panel wipe

3. 240 grit paper for keying up then panel wipe

4. Etch primer rubbing down between layers x 2

5. Seam sealer on weld joins

6. Top coat

is this a fail safe but basic way of going about it all?

[sal]

No point in two coats of etch primer. Just one light coat to bite into the metal.

For a repair that is unseen I use
Etch primer
Zinc primer
Seam sealer (pu from tube. Drop in hot water before use)
Top coat which can be aerosol, stone chip etc
Waxoyl

[slater]

frosts sell a product called Metal Ready. It's a phosphoric acid that converts any left over rust to help stop it coming back through. I always use a bit of that before painting. You won't get rid of all the rust by sanding alone so pays to use somthing like that before you paint.