Underside Treatment

[mhyphenl 10 1 Cars]

I've just about finished stripping my car completely and want to get to grips with what to do to prepare and rennovate the underside of the car. I have rust in the usual crevices, above the spare tyre and petrol tank, what sould be the first steps,? ie stripping the underseal and dealing with the rust. How would you remove the rust in the crevices and treat it to prevent it reoccuring.

any advice

[2-Pugs 57]

Hi Martin

 

I have no personal experience of this lot but they always good write-ups in Practical Classics and the like:

 

http://www.bilthamber.com/

 

I keep thinking of buying some of their products and trying it out.

 

Any rust I would either scrub off with one of those grinder wire brush things. Or use the Deox Gel or Hydrate 80 noted above. Then coat with the cavity wax.

Edited March 13, 2010 by 2-Pugs

[jord294 87]

i've used products from here for my resto project

 

http://www.rust.co.uk/epoxy-mastic.cfm

[toddydal 1]

my boss has been doing mk 1 and mk 2 escorts and we got a guy in to media blast all the underseal off,,

[boombang 2]

I did the entire underside of my shell - it was a nightmare job, very very messy and took many hours.

 

Used a wire wheel on an angle grinder - it tears through the underseal and any surface rust

 

MAKE SURE YOU WEAR FULL PPE!

 

Then dress any left over surface rust with a Bilt Hamber product, then zinc primer, then paint & underseal. I used Shutz for self healing properties, but again it's very messy.

 

Areas without any rust you can use a normal etch primer before painting and undersealing.

[2-Pugs 57]

It's times like this when you need one of these....

 

 

(the jig not the car...)

[Redtop 14 2 Cars]

It's times like this when you need one of these....

 

 

(the jig not the car...)

 

 

Has anybody ever made a spit for a 205? I have one for mk2 escorts etc but I was looking at making brackets for it to take a 205 but you'd have to bolt through the 8mm holes that the bumper brackets go through into the boot. The front would be easy enough to make though. I'd be worried of the rear being abit weak?

[2-Pugs 57]

Could you not use the subframe mountings?

 

Or do you need to have fixings on the end 'faces' of the shell?

 

As you say I am not sure how strong the rear bumper area would be to fix to.

[davepug205 7]

Ive just made one last week like you say the rear bumper mounts are flimsey.

I used the rear seatbelt holes in the boot, I made a bar to fit between them with a thread in each end to attact the body. I made it stiff enough to turn easily without locking pins etc

[mhyphenl 10 1 Cars]

It's times like this when you need one of these....

 

 

(the jig not the car...)

 

Hi Rob, Hows things?

 

 

Ha, you're not wrong!

 

I managed to strip all but the engine bay yesterday. Thats all fairly straight forward. I'll need to be organised for the wiring and engine! lots of labeling and photo's.

On subject, I managed to find someone to media blast and etch prime the whole car in and out for £450! It's through a customer at work, does this sound like a good deal? Dipping and priming was going to be £1300+ which was simply not going to happen!

[MerlinGTI 3]

£450 for inside and out blast + etch sounds good to me.

 

Most media can make a right mess of body panels though, making extensive prep necessary. Vapor or soda blasting seem to be the way forward here.

 

Dipping (usually followed by zinc galvanising) is lots more expensive but the results are in a completely different league.

 

Im doing the underside of my car soon and heres the prep product list so far:

 

Granville Rust converter

U-POL Acid 8 etch primer

U-POL Hi-Build primer

Tetrosyl 4 in 1 seam sealer

Tetrosyl white stone chip / underseal

[mhyphenl 10 1 Cars]

£450 for inside and out blast + etch sounds good to me.

 

Most media can make a right mess of body panels though, making extensive prep necessary. Vapor or soda blasting seem to be the way forward here.

 

I'm a little worried about panel damage, the guy seems to think that using a plastic media works due to low heat and it being less aggressive. If anyone knows otherwise please tell me soon!!

 

On Soda blasting, there seems to be alot if concern that it leaves a residue behind which in the short term protects from flash rusting but is almost impossible to completely remove. This has led to poor adhesion and paint lifting after a year or so.

 

Are you doing the underside yourself? What prep are you doing and how?

[mr_exe 1]

Finnigans Underbody Sealant with addded Waxoyl. Both me and the car got well covered

[MerlinGTI 3]

I'm a little worried about panel damage, the guy seems to think that using a plastic media works due to low heat and it being less aggressive. If anyone knows otherwise please tell me soon!!

 

On Soda blasting, there seems to be alot if concern that it leaves a residue behind which in the short term protects from flash rusting but is almost impossible to completely remove. This has led to poor adhesion and paint lifting after a year or so.

 

Are you doing the underside yourself? What prep are you doing and how?

 

Thats something I didnt consider about soda blasting! Im sure a lot depends on how meticulous you are with the panel wipe & scotch (theres got to be 2 days worth of this on a full shell I would guess-timate), but even still theres going to be some places you cant get that the soda did I suppose!

 

I will be doing the underside myself.

Restrictions im being faced with are not having a garage (or a drive for that matter!) and not wanting to strip the car completely (rules out a 'spit').

 

Plan is to completely strip the underside upto the front subframe (when new engine goes in the remaining front portion of the car will be done)

Attack the underside with various air tool attachments:

 

Like this

This

& This

 

Treat any signs of rust with Granville.

I have a patch about the size of a 50p under my fuel tank that needs chopping out and welding

Scotch and wipe down with panel wipe

Acid etch prime

Seam seal

High build prime.

 

At this stage I will be refitting (and getting off my father in laws drive!) with new beam\pipes etc...

 

Driving the car to my mates bodyshop, sticking it on the ramp, stripping (parts off) again, stone chipping and finially spraying in body colour in HS. Rebuild sorted

[harryskid 193]

I did mine the hard way, scraping sanding wirebrushing. Treating surface rust under sealing wax oiling ect. It took ages plus i had alot of welding to do and i was only using mine for rallying. 450 might sound a lot but if you get a good job and you want a mint car i would think it would be well worth it. After the mess and time mine took if i had known of this method i would have been tempted and if i do another i might give it a try. I think i would get a few more prices though if i were you. Good luck with your project.

Harryskid

[mhyphenl 10 1 Cars]

Yep, for that price I'm really not interested in lying under my car for a couple of weeks doing the underside plus all the effort in doing the topside and inside. When its acid etch primed is it at that stage that i do minor filling jobs, obviously any welding jobs need to be done before I take it to him!