Inside inner wheel arch - hammerite stonechip shield?

[jb2000]

The inner wheel arch has an outer 2-inch with no stonechip (just a flaking black cellulose), the rest is entirely rubbery stonechip.

3M clean-n-strip disc...
- Black cellulose area had thin film of rust, but easily achieved bright steel with a few pinholes coinciding oddly enough with tiny dents!
- Rubbery stonechip area had perfect bright metal, no corrosion undercut.

I plan on...
- Vactan (tannic acid corrosion stopper) to kill any corrosion in the pinholes
- Clean-n-strip the Vactan off, leaving neutralised pinholes
- Fosroc Galvafroid Zinc brushed (as I have no Bondaprimer Zinc spray left)
- Galvanised paint primer (yellow)
- Hammerite Stonechip Shield (grey, overpaintable)

Instead of Galvafroid I could use Plastikote 90% Zinc aerosol, but prefer to use that "between jobs through bad weather". Zinc must contact base metal, any insulating effect eliminates its electrochemical protection (and galvafroid does work surprisingly well from experience).

Q - If I ever have to weld again, how easy is it to remove Hammerite Stonechip Shield?

I suspect it will be easy to remove because of the underlying galvafroid will be mechanically weak in shear, I just want an impact overcoating. Most would use Lechsys 2k Zinc Epoxy but I am wary of an epoxy near where I may need to do future welding - why add more work before I am done :-)

 

[steveo3002]

id not worry about getting it off , use the best you can

if its rusty in xx years time im sure a grinder will see to it

 

[jb2000]

Noted, the galvafroid would act as a shear layer anyway.

I have memories of Sikaflex you see... "removal by mechanical or nuclear weapon only"... a bit like cleaning up after an expanding foam truck falls over.

 

[steveo3002]

whats with the 2 seperate galv paints ...surley no point for one over another?

 

[jb2000]

Fosrock Galvafroid - 96% zinc.
Galvanised Metal Primer - 0% zinc, stabilises & gives a base to bond to.

I suspect you mean Hammerite Stonechip Shield sticks to Galvafroid?
Not sure... chlorinated rubber paint does stick to Galvafroid.

 

[steveo3002]

ah yes i see ..id read it wrong ...i saw 2x galvanising primer

 

[jb2000]

Just a note re Vactan, a tannic acid rust convertor WITH primer.

It is VERY VERY good if you want to put paint directly over the top.
Converts rust well, waterproof, VERY tough, VERY difficult to remove with a clean-n-strip disc back to shiny steel. A very good product at bargain price.

It is not suitable if you want a quick rust-pit converter before you whiz over with a clean-n-strip disc to shiny steel for zinc coating. Stick with plain phosphoric acid products like Kurust.