Hydrate 80 what amount?

[hardhatharry]

As I am going back to bare metal and reading other build threads I see Hydrate 80 seems to be the rust protector of choice.

Do I cover the whole car in it prior to etch primer?

How much should I purchase to cover a spitfire? It comes in 500ml, 1ltr and 5ltr containers.

[Badwolf]

I have a 1ltr pot and have covered the whole bonnet nearly twice (don't ask??!!), and part of the hard top. I have used about 1 inch out of the pot. It is very economical. I plan to go over it with a P80 disc on my DA sander before painting over in 2k primer/filler. As you may have seen, there is not a great deal of rust on the bonnet and anything 'below level' will retain the H80 treatment in full. Any mild surface rust should go just before I prime. The hardtop is a different matter as it is badly rusted in places and I will be looking into that shortly. Hope this helps a bit.

Addition-

Decant a small amount into a none metal container for use, do no return anything left over to the main pot. Ensure that the threads of both pot and lid are clean before putting the top on, it is known to glue the lid on!!! I had trouble getting the top off from the start.

Edited August 3, 2020 by Badwolf
Addition

[Paul H]

I think Hydrate 80 has been superceded by Deox C . I suggest you contact Bilthamber using their contact form . They are very helpful , takes a couple of days to get a reply 

Paul 

[Badwolf]

Paul - Deox-C is normally used as a gel, more useful for vertical panels. I believe that it is mostly citric acid in suspension but not sure. (I did read elsewhere that people were adding citric acid powder to wallpaper paste to make thier own). H80 is a thin liquid. I have both but use mainly the H80. There is a comparison here...

https://www.bilthamber.com/which-corrosion-treatment

[Paul H]

My apologies Hydrox 80 is stlll available it’s just been moved around on the site 🤗

i would still make contact with them 

Paul 

[hardhatharry]

Do I apply the seam sealer before applying this?

[Badwolf]

No apologies needed. The B/H page that I posted also recommended deox-c crystals in solution for use in dipping tanks/trays which I omitted to mention. I have just done my bonnet with Hydrate 80. It is really weird stuff. Goes on light blue, rapidly turns dark, then cures to almost black.  It also does keave brush marks, so I will flash over it to smooth with a P80 disc clean off and panel wipe just before I apply the 2k primer.

[Badwolf]

Just now, hardhatharry said:

Do I apply the seam sealer before applying this?

I am not sure, but feel that you need to get any rust preventative in there before trapping anything under the seam sealer. No doubt someone will be along to advise better than me in due course. I have not got to that bit yet! Sitting waiting for my replacement paint stripping discs to arrive. Don't mention 'Hermes'!!  ...ggrrr

[hardhatharry]

Is Hydrate 80 weld through or does it need to be ground back to weld?

[Badwolf]

Sorry, that I don't know.

[chrishawley]

The data sheet for Hydrate 80 is oblique as to what it contains. But most likely it'll be based around phosphoric, oxalic acid or citric acid or something like that. Any of these will tend to create a non conductive coating that can be a hindrance rather than help for welding. Clean metal always welds better!

I use Jenolite for surface prep then just quickly clean the welding faces with a scourer (e.g. Scotchbrite). Fine for MIG. Then, wherever the joint is accessible, work in a rust inhibiting primer (e.g. Bondaprimer) with a fine artist's brush.