Rust Treatment & Underseal.

e-bygum · Post by **e-bygum** » Wed Oct 21, 2009 2:55 pm

When I took the IRS out I found the radius arm mount rusted through on the RHS. Before the car goes to have this fixed I decided to stip of all the old underseal in the rear wheel arches and above the IRS to check if there were any other areas that needed attention. Fortunately there is no more severe rot but there are several areas of surface rust, it looks like a patchwork of bright shiney metal, original primer and the surface rust. All except the rust areas are smeared with the residue of the underseal. I had intended to paint the whole area with POR15 and then re-underseal over it. I don't think it will be practical to attempt to manually clean it all down to bare metal.
Questions:
What can I effectively use to clean off the remains of the underseal so that I can paint?
What would you recommend I paint it with as from passed experience POR15 does not seem to adhere very well to the primer? (but that could be my fault)
What would you use to treat the rust before applying a paint? I'm scared to use phosphoric acid as I'll be working above my head.

vacbag · Post by **vacbag** » Wed Oct 21, 2009 3:11 pm

Hello Pete. :D
When I carried the same operation I used a mini grinder with a cup wire wheel to remove the underseal and any rust and then Phosphoric acid. Do not worry about working above you just use goggles and gloves, if you get it on your skin it will not burn but it will make you black. 8)

Steve.
Sunny Scarborough UK.

christopher storey · Post by **christopher storey** » Thu Oct 22, 2009 7:46 am

I agree with Steve. H2PO4 will do you no harm. It stings in any cuts, and is best avoided in the eyes, but irrigation with water is a good remedy. It is best to use it in a 10% dilute solution when for some reason it seems to be more effective than at full strength.Leave for 24 hours and then wipe down with wet cloths

e-bygum · Post by **e-bygum** » Thu Oct 22, 2009 2:23 pm

christopher storey wrote:I agree with Steve. H2PO4 will do you no harm. It stings in any cuts, and is best avoided in the eyes, but irrigation with water is a good remedy. It is best to use it in a 10% dilute solution when for some reason it seems to be more effective than at full strength.Leave for 24 hours and then wipe down with wet cloths

Steve, Christopher
When you say Phosphoric Acid are you talking of a rust removal product containing the acid or the straight chemical? If the chemical, where do you get it from?
I have used Clark's Rust Remover (which is Phosphoric Acid based) but it needs to be kept wet in order to work properly. This is ok if the rusty part can be immersed but would mean applying it frequently in the wheel arches and above the IRS where it would run off.
Does straight acid remain active if it dries on the metal or does one have to keep 'refreshing ' it?
What would you paint the area with after treating the rust?

daverawle · Post by **daverawle** » Thu Oct 22, 2009 3:54 pm

e-bygum wrote:
Steve, Christopher
When you say Phosphoric Acid are you talking of a rust removal product containing the acid or the straight chemical? If the chemical, where do you get it from?
I have used Clark's Rust Remover (which is Phosphoric Acid based) but it needs to be kept wet in order to work properly. This is ok if the rusty part can be immersed but would mean applying it frequently in the wheel arches and above the IRS where it would run off.
Does straight acid remain active if it dries on the metal or does one have to keep 'refreshing ' it?
What would you paint the area with after treating the rust?

Mix it with wallpaper paste, that stops it running and it stays wet.
Dave

e-bygum · Post by **e-bygum** » Thu Oct 22, 2009 4:11 pm

Thanks Dave.
What a damn good idea, assuming you're serious.

daverawle · Post by **daverawle** » Thu Oct 22, 2009 4:29 pm

e-bygum wrote:Thanks Dave.
What a damn good idea, assuming you're serious.

Pete,

It's a method for keeping paint stripper in place but I don't see why it shouldn't work with rust remover as well.

Dave

e-bygum · Post by **e-bygum** » Thu Oct 22, 2009 4:51 pm

Dave
I'll mix up some wallpaper paste flakes with my Clark's Rust Remover and give it a try.

Post by **Heuer** » Thu Oct 22, 2009 5:38 pm

e-bygum wrote:Dave
I'll mix up some wallpaper paste flakes with my Clark's Rust Remover and give it a try.

:bang:

Larry Wade · Post by **Larry Wade** » Fri Oct 23, 2009 12:12 am

Hi Guys,

I would never use an acid unless it was completely neutralized after use. If not completely removed or neutralized it will continue to eat at the metal in years to come.

Larry

MarkE · Post by **MarkE** » Fri Oct 23, 2009 8:57 am

Phosphoric acid is neutralised when exposed to oxygen, and converts iron oxide (active rust) into iron phosphate, chemically stopping the oxidation process. When applied to clean shinny metal, it just converts to a layer of phosphate on the clean metal, which provides protection for bare metal for years. There is no danger of it eating away at the metal?it isn?t acid any more.

I stripped my Coupe shell, and as each panel was revealed, I painted it with Jenolite, a gel suspension of phosphoric acid. Nothing much happened in the bodyshop for a couple of years and the shell was left bare in the corner of the shop and was absolutely fine, with no rust appearing. Probably no big deal in a dry climate, but here in the UK, with damp winters, that?s absolutely amazing.

Phosphoric acid doesn?t have any etching properties, so a base etch-coat has to be applied after all the phosphate has been removed (by sanding).

It lasts very well, and on cars that I?ve had for 20 plus years where I?ve used this stuff, in combination with Waxoil when underneath the car, there has been no deterioration at all.

This is what the body looks like after being coated in Jenolite:

christopher storey · Post by **christopher storey** » Fri Oct 23, 2009 6:27 pm

Pete ; David Rawle's idea of wallpaper paste is a good one , but check that the paste is not alkaline before using or it will neutralise the acid

I use actual Phosphoric Acid. I bought 25 litres of it some years ago from an agricultural supplier which is probably your best bet, although any commercial chemical supplier will probably supply you - it is minimum quantities which are likely to be the difficulty

Alternatively, if you come along the Wirral at all, ( I wouldn't post it) and only want a small amount for this particular job, I will gladly give you some . E mail me on cstoreyqc@aol.com or ring me on 0151 342 3175

Incidentally, it is also extremely good for cleaning brake dust off and de rusting chrome wheels

e-bygum · Post by **e-bygum** » Fri Oct 23, 2009 9:38 pm

I mixed up some Solvite with Clark's Rust Remover today and gave it a try. It worked equally well in shifting the rust as does the Rust Remover alone. It did not stick very well to the under side of horizontal surfaces. I think I may have used too much Solvite as it did not produce a thick liquid like Solvite and water but more as if the flakes did not completely dissolve and combine together. It was easier to apply it with a trowel than a brush. I'll try it again tomorrow using less Solvite.

Christopher
Thanks for the offer. I'll try to get some acid locally and if unsuccessful may take you up on it.

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

The 'E' Type Forum

Rust Treatment & Underseal.

#1 Rust Treatment & Underseal.

#2 Underseal removal

#3

#4

#5

#6

#7

#8

#9

#10 Rust Treatment

#11

#12

#13