Acid dipping advice

[mph]

Paracetamol said:

http://www.envirostripukltd.com/portfolio/auto-res...

The garage that are restoring my 61 Flat Floor E Type are using this company for the stripping.

They claim the following

No harsh chemicals are trapped in the seams & box section which can cause issues later in life
No indentation to the shell from shot blasting
No sand / grit trapped in seam joints
Saves time and money for the customer when the shell goes into the paint shop
The body shell stays on one secure process frame throughout the process eliminating any damage to the shell

Personally I wouldn't have any car acid dipped.

A bit of grit or sand trapped in a seam is hardly an issue and any professional blasting company should be able to remove paint and corrosion without damaging the panels. Even if some damage is caused it can be rectified during the restoration.

Residual chemical is potentially a huge problem. It will manifest itself long after the car is restored and painted. How do you sort that out ?

[davepoth]

I have something I think I can add to this. My car (Triumph Dolomite) was dipped in 2004 by Surface Processing. I got it primed (not the e-coat) by SPL, and then sprayed a month or so later. Because I'm so bloody feckless the shell has been sat in a reasonably well ventilated (although the bottom of the door does leak when it rains a bit) council lockup since then, so I think it represents a fairly good "control" since road usage hasn't been an issue. One bonus to being crap at restoring I suppose.

I've looked fairly closely over the car and there is some light rust coming out of one or two seams where it wouldn't be possible for the paint to penetrate properly. I have the same kind of rust pattern in similar seams on my 11 year old daily drive so I don't think this is down to the acid dipping.

There is however one single rust spot which I think might be down to the acid dipping. there's a spot on the floor where a corrugated panel sits on top of a flat one. It's not a known rust spot for these cars (although it really is an excellent rust trap), and as I say most of the other rust causes aren't an issue for this shell. I can't confirm it's the acid dipping, but it seems it might be possible that some acid didn't drain out of that particular spot and ate at the metal.

That said, it's a 10 year old paint job on a 40 year old British car, so I think the shell has held up pretty well all things considered.

[windy1]

I've come to the conclusion that the horror stories doing the rounds on the forums about dipping are coming from people that have no direct experience of the process. There are a few cars I've looked at that have been dipped and they've never had any paint issues, but they were all properly e-coated as part of the process. These cars are probably better protected now from rust than when they were new.

[mph]

windy1 said:

I've come to the conclusion that the horror stories doing the rounds on the forums about dipping are coming from people that have no direct experience of the process. There are a few cars I've looked at that have been dipped and they've never had any paint issues, but they were all properly e-coated as part of the process. These cars are probably better protected now from rust than when they were new.

Are you in the trade to have knowledge of several cars in detail ?

You only have to go back one page on this thread to see real examples.

It's possible, even probable, that these are isolated incidents but personally I still wouldn't take the risk when more conventional methods are available and effective.

[vpr]

windy1 said:

I've come to the conclusion that the horror stories doing the rounds on the forums about dipping are coming from people that have no direct experience of the process. There are a few cars I've looked at that have been dipped and they've never had any paint issues, but they were all properly e-coated as part of the process. These cars are probably better protected now from rust than when they were new.

I think you need to go back and read properly

My case is very real and after spending 80k on a resto (incidentally a rust free car from CA which needed no metal at all) I was gutted....And remember my car has not seen a drop of water and has been kept in a dry dehumidified garage

My car saw the whole process including e-coating and the distortion of panels where they clumped it in their tanks

I will try and find the other "real case" on the etype forum

[droopsnoot]

I must admit that I've also seen quite a few horror stories either as a result of acid seeping out of box sections and seams later on, or about damage to the shell while it's being moved around the dippers premises. But that might just be the nature of forums in general - people may be more likely to write about a bad experience than a good one. I've also heard there's a major manufacturer that uses the services of one of the dipping companies - I can't remember which one - which might make you think there has been some proper assessment of the process before they signed on.

[ShiningWit]

droopsnoot said:

I've also heard there's a major manufacturer that uses the services of one of the dipping companies - I can't remember which one - which might make you think there has been some proper assessment of the process before they signed on.

Why would a major manufacturer be dipping old rusty shells?

[mph]

ShiningWit said:

Why would a major manufacturer be dipping old rusty shells?

Yes, British Leyland went out of business years ago

[droopsnoot]

ShiningWit said:

droopsnoot said:

I've also heard there's a major manufacturer that uses the services of one of the dipping companies - I can't remember which one - which might make you think there has been some proper assessment of the process before they signed on.

Why would a major manufacturer be dipping old rusty shells?

I can't remember, and that's why I didn't say who it was. I think the idea was that they were dipping new shells but I can't remember the reason why. I'm going to the Restoration Show tomorrow, so if I find the same person on the same stand to ask them, I'll find out more.

[jagracer]

droopsnoot said:

I must admit that I've also seen quite a few horror stories either as a result of acid seeping out of box sections and seams later on, or about damage to the shell while it's being moved around the dippers premises. But that might just be the nature of forums in general - people may be more likely to write about a bad experience than a good one. I've also heard there's a major manufacturer that uses the services of one of the dipping companies - I can't remember which one - which might make you think there has been some proper assessment of the process before they signed on.

I've seen two cars that have been dipped and both didn't turn out so well. OK they both came out stripped right back to bare metal but as has been said the acid keeps running out and the body never stops rusting in places. I think the manufacturer that used one of the dipping companies was also did a reciprocal service of e coating them or whatever It's called. I also believe the company went out of business so as of sometime last year you cant get a body e coated after It's been dipped. I've also heard a few negative things (also seen it on one body) about the bodies being damaged in the dip bath or in handling.

droopsnoot said:

I think the idea was that they were dipping new shells but I can't remember the reason why.

A new shell would need to be dipped before it can be coated.

Edited by jagracer on Saturday 28th March 18:56

[Mr_B]

Kevin Leaper over at Practical Performance Car magazine had his MGB shell dipped and e-coated by SPL years ago. I emailed him regarding this as he still hasn't got around to doing anything with the shell and it sits inside in just the e-coat and seemed as if it was on some kinda long term test.
I've been looking at using SPL if I ever start my own project and thought I'd ask his thoughts. He was kind enough to reply and seemed very positive and said there was some small amount of rust, but thought it acceptable given the shell had sat for years when it should should have been painted.

I've seen a couple of people have shell done and e-coated by SPL on another forum and asked both for their thoughts. Both reported no problems with rust or acid leaching, but both did report problems and damage during the handling of the shell during the process, one of which was a dent in an expensively replaced complete roof panel change.

[droopsnoot]

I didn't talk to anyone at the show yesterday so I can't shed any light on the comment I made about dipping new shells.