Epoxy primer / bilt hamber s80 questions

bigegg · 2026-04-17T12:07:53+0100

I am currently tidying up my land cruiser:

Thread 'Land cruiser 100 Amazon bodywork'

Wednesday at 6:54 PM

Finally reached a point where all the mechanicals are done on my Amazon, so started on the cosmetics.

Inner wings are pretty spotless.
(Thank dog!)

Quick blast over with the pressure washer and a over spray with my favourite cold galvanising paint.

I've reached the point on the front panels where all the bad patches have been replaced, the pinholes have been filled (with weld!) and the surface rust has been wire wheeled/ground out.

I have liberally coated all the bare metal in bilt-hamber S80, and am ready to epoxy filler prime with hempel 45141

I'm planning to brush the primer on - the panel will be skimmed over with isopon filler in a couple of weeks, then I'm going to enamel coach paint over the top, and I'm not overly bothered about a pristine finish - durability is a greater consideration.

The bilt-hamber stuff specifically mentions it is suitable for over-coating with epoxy.

Given the above:

Should I coat the entire panel with S80 (over the OEM paint) then prime?
Or will that just be a waste of S80?

I'm going to scuff up the existing paint with ?120? grit for the epoxy to bond. Is this correct? ? Or should I go for 80? 240?

I'm intending to epoxy prime the entire panel, and I don't really want to remove *all* the paint + potentially the galvanising given that most of it is in good condition.

Any other advice/comments appreciated.
I paint miniature figures with acrylics usually - not full size cars!

marlinspike · 2026-04-17T13:15:40+0100

Do you mean Hydrate 80, the BH rust convertor/encapsulator? I only use it on rusty bits. I feel it's wasted on good metal. I have brushed 2k epoxy over it with no issues. I've sprayed aerosol 1k high zinc primer over it without issue too.

Not sure about the keying of the rest of the panel but I think those grades are too abrasive. I think it was on here that I read: 'Remember, you'll have to remove every scratch you sand in...' or similar. I'd start with something a lot milder, like 400. You can always go more abrasive.

steveo3002 · 2026-04-17T13:23:56+0100

i only use the convertors as a last resort when it cant be cleaned /fixed properly in the hopes it does a little something (im not convinced it does a great deal apart from turning things black )

on open areas id prefer the epoxy to go direct onto the cleaned up steel otherwise your losing the benefits of using it

bigegg · 2026-04-17T13:43:10+0100

marlinspike said:
Do you mean Hydrate 80, the BH rust convertor/encapsulator?

Yes - hydrate 80.

I'm putting it over the sanded back areas just to make sure the worst pitted areas are scrupulously clean of rust.

steveo3002 · 2026-04-17T14:08:43+0100

why not use the deox gel to remove rust instead? or at least where its accessible

ajlelectronics · 2026-04-17T14:11:49+0100

bigegg said:
I'm going to scuff up the existing paint with ?120? grit for the epoxy to bond. Is this correct? ? Or should I go for 80? 240?

Lechler is 120-180 for initial coats on bare substrate. Sealing coats are 240 grit (all dry). I would imagine that most epoxies are going to want similar treatment.