View Full Version : acid dipping

07-10-2006, 01:44 PM
Who knows anything about this? As my car is a god awful colour, and been an ex rally car has loads of underseal on it, I quite fancy stripping it back to bare metal and respraying it. I've heard about acid dipping before, and figure it is quite a simple "chuck it in a vat of acid" type thing, but are there any disadvantages? And does anyone know anywhere that does it and what sort of costs are involved?

Darren Langeveld
07-10-2006, 06:19 PM
Didn't Porsche used to acid dip the 917 shells to strip a few kilos off them?

Listen mate - it sounds pretty extreme, involves dipping the whole shell into a vat and if you leave it in for too long it will be a holy mess.

A bit like Gary's.

Are you sure you don't want the shell bead blasted back to bare metal?

08-10-2006, 11:14 AM
could do! anything to remove the inch thick underseal without taking me weeks...?

08-10-2006, 11:47 AM
I'm looking at doing this right now with the M3. Email this company and they will reply with a prices and pictures of cars they have treated. Sadly their website is total crap and says nothing. www.surfaceprocessing.co.uk Here is their reply to me....



Our process was initially designed for the purpose of cleaning rally shells for Prodrive. However we now process high volumes of classic car shells, from Austin Healy 3000, Alfa Romeo, MGA, Porsche and BMWS. Modern day vehicles have been designed for Electrophoretic priming and hence these have adequate drainage. Classic vehicles were made with box section and were historically painted with primer by hand.
In order for us to process a classic shell we would firstly recommend any box section on the shell should have 6mm holes on both ends of the section to allow drainage in an out. This would then allow the process to penetrate any hollow section cleaning all the cavities. Finally each section would be washed out using a high pressure rinse whilst applying a rust inhibitor solution in the water.
We can also apply an acid etch primer or an electrophoretic primer at additional cost. Leaflet attached.
A standard BMW 3 series shell would cost 675.00 to strip.
To oven dry and acid etch prime 300.00
Electrophoretic prime 750.00
All prices subject to VAT.
Please find attached photographs of various vehicles


I also looked at having the shell blast cleaned with www.centralblastcleaning.co.uk The cost was a bit less for a full inside and out clean and prime than the acid dip and E-coat. The pain with blast cleaning is that I would have to strip all the underseal off,which would be a pain in the bum and would also mean fabbing some kinda chassis rotisserie,so the acid dip and E-coat is the fave at the mo.
Here is the reply I got from CBC.




If there is no underseal on the car we can blast the underneath the inside the engine bay all door shuts and window reveals the cost for that is aprox 395.00 + vat. we can carry out a bare metal strip and prime including all body panels i.e. roof rear quarters cost 1160 + vat depending on the next stage as we do not recommend leaving a car in primer for any length of time as most primers are porous. if you need any more information please call me on 01295 278233 or 07767 767 089
Regards Mick.


08-10-2006, 08:15 PM
Excellent, thats just what I wanted to know. When they say 675.00 to 'strip' the shell, I take it that is the acid dipping part? Not stripping the shell of all the parts? So, 675 to strip and 750 to prime? Or 1160 with the blasting company? Thats right yeah?

Cheers, Pete

08-10-2006, 09:19 PM
I'm no expert at this,but from my understanding you will want the shell in primer ASAP, or you can expect rust within hours of a freshly dipped or blasted shell. The strip price quoted ( 675 ) is just to acid dip the car. You would have to bare shell the car yourself. The same also goes for media blasting,except you also need to remove the underseal yourself or possibly pay them to manually scrape it all off . The blasting price quoted was for me to deliver a bare shell without underseal.

With the media blast you have several option on how much you want blasted,which of course, can work out cheaper. Some people have advised I don't bother getting the roof and rear quaters blasted if there is no rust,as blasting roof panels can warp them if not done correctly. If I were to go the blast route,I'd have the underside,engine bay,sills ,window sealing areas, and generally all the edges and lower parts done,as it's unlikely to have rust in the roof or rear quaters or center of any large panel.

I'd like to visit the acid dip place and see a shell go thru their process. I'm not sure how you can fully protect a dipped shell if you pay for the cheaper ( 300 )etch prime,as I'm guessing this is spray applied. The E-coat prime is a dip process,so will get in every area.But like I say,I've still to find out the full details.


Darren Langeveld
09-10-2006, 03:35 PM
That'll save your missus having to do it Pete!

Gary Kinghorn
10-10-2006, 11:11 AM
If I acid dipped the beemer there would be nothing left of it ;)

10-10-2006, 03:19 PM
Originally posted by Gutmann pug@Oct 10 2006, 11:11 AM
If I acid dipped the beemer there would be nothing left of it ;)
Amen dude.

rust is lighter than titainium :thumb:

as for your sig, should it not read...or you're gutmann_pug trying to remove a sunroof cage :whistle:

25-10-2006, 08:34 PM
SP have updater thier site to include full details and pics of various examples.