Opinion on Bilt Hamber rust treatments?

[Five_Star]

How do people rate the Bilt Hamber anti-corrosion treatments, specifically I’m looking at using either their Deox-GEL or the Hydrate 80 treatments on some rust pitting around the rear arches.

I’m concerned the edges of the arch lip at the top are quite thin and delicate so don’t really want to remove more material than I need, but at the same time would like to cure the rust before it gets any worse!

Top of arch


Bottom edge corner

 

[bainbridge]

18mths ago on my rear arches I used 2 coats of Bilthamber Electrox zinc primer followed by 2 coats of Bilthamber mastic epoxy, and no rust has reappeared. The only problem is I haven't driven it daily through the winter as I normally would, due to WFH.

Sorry I've not used the other products you mentioned.

 

[SkodaMart]

I bought the polish once.
Basically like rubbing wool fat into my paint
Needless to say I didn’t use it again.

 

[DRZ]

I have used both Hydrate 80 and Deox Gel extensively and at least in my experience there's nothing better.

Like anything, prep is key. If you just apply H80 to loose flaking rust patches it won't last. Deox C/Gel and then electrox primer is the best but again you need to make sure you're back to good metal and follow the directions properly.

 

[Tom_ed1987]

I wasn't that impressed with the hydrate 80. It's fine for internal use, patching up, & preventing things getting worse I suppose, but it's water based & not a very long lasting treatment IMO. Deox is really good & gets similar results to using acid. The Deox powder might actually be just citric acid, i'm not sure.

If that arch lip is a single skin then that is a fairly easy repair. - I'd just grind off the rusty bits & coat with something. If a double skin, to get a long lasting repair you'll have to drill out all the spot welds, very carefully pry the two skins apart, mechanically remove all rust with a Dremel or similar, use deox-c/phosphoric acid to rid it of any traces of remaining rust, then either use weld through primer & remake the spot welds, or my preferred method - remake the joint using clamps & panel bonding adhesive.

 

[adam cool dude]

The only way you are going to get rid of that is it to grind it back to bare metal. Treat it with some form of rust convertor on the pits that may have been missed then spray over with bilt hamber electrox and paint on top.

A bit more extreme than yours but I just repaired my rear arches and the bit that meets the door.



My steps were;

-Grind it back to good metal
-Cut out rusty stuff.
-Weld in new metal.
-Electrox both sides.
-Seam sealer over everything.
-Stonechip.
-Paint & Lacquer.

As you can see my arches were barely rusty appart from the bottom edge that meets the door. Worth taking out your arch liners to check behind there as well.

 

[jpaul]

Treat it with some form of rust convertor on the pits that may have been missed

this seems like the difficult point - deox-gel seems to be just a citric acid formulation ( some people try wallpaper paste + citric acid)
as opposed to a convertor .. where you get some kind of black rust 'conversion'.

I used frameto(gos black) on a previous repair that lasted 3 years, this time used a u-pol acid primer and it is showing bubble through after 8 months,
was planning to use some david's anti-rust 182 primer this time, when weather co-operates.

top coat resilience(impermeable & projectile resistant) seems important ... to wit

18mths ago on my rear arches I used 2 coats of Bilthamber Electrox zinc primer followed by 2 coats of Bilthamber mastic epoxy, and no rust has reappeared. The only problem is I haven't driven it daily through the winter as I normally would, due to WFH.

although mastic expoxy sounds good/ideal for resiliance to wheel arch environment, is it a faff to mix and clean-up?
... seems to need another thinner ... another one to add to my collection.


edit:

Top of arch

forgot to ask - is that some kind of fibrous/bitumen on the inside of the panel ... is it going to strip back easily ?

 

[Five_Star]

@jpaul the arch liner is a fabric type affair that removes fairly easily so should be no issue to see the full extent of the problem.

I was thinking that the epoxy might have improved impact resistance on the arch edge. I think I'll be going with the deox gel / electrox primer / epoxy top given peoples suggestions on here, very helpful

 

[jpaul]

Finally got round to doing some bike rust patches

- drill wire brush, IPA degrease
- loctite/frameto rust convertor 7500
- Davids' zinc 182

really surprised how thick the Davids is, as a primer !
whilst it is going to make the surface gravel/projectile resistant, it may need some sanding down before a top coat.

 

[bainbridge]

Update on Bilthamber products:

The epoxy resin on my rear arches and underside of the bootlid has started to lift and flake away But the Electrox zinc primer below is still solid. It appears that road salt over the winter somehow got under the mastic epoxy, or maybe dried it out, but the Electrox is holding up well.

I might grind back the areas yet again, treat with rust converter and apply 2 coats of Electrox and leave it. It'll be a primer finish but the areas aren't readily visible.