Sand blasting a car shell
Sand blasting a car shell
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Discussion

ellis427

Original Poster:

1,653 posts

205 months

Friday 10th May 2013
quotequote all
Alright guys!

So...
I have a car shell that I am going to build into well something special. It's already a bare shell, so I want to have it sand blasted down to the metal, before I start toying with it!

A. Does anyone know, or used anybody who is really good at this sort of thing? (If done wrong can do some serious damage) and if so what sort of prices are we looking at here?

B. would it be best to sand blast the whole shell, then put full roll cage in before having it painting? Or after sand blasting to metal have it sprayed in side and out then cut all the holes and put cage all the way through?

Cheers for any replies

Matt

McWigglebum4th

32,414 posts

230 months

Friday 10th May 2013
quotequote all
i would not sand blast a car shell

Glass blast maybe

Soda blast even better

Not sand as its too aggressive

pobox205

209 posts

158 months

Friday 10th May 2013
quotequote all
Put the cage in before any body prep is done.

SMcP114

2,916 posts

218 months

Friday 10th May 2013
quotequote all
I had the majority of my shell sandblasted, just so I knew exactly what I had. I was told not to, that panels would be damaged etc etc, but the car turned out flawless.

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

From memory it was between £200 - £250, soda blasting was a lot more expensive and not as readily available. I highly recommend it.


Lugy

830 posts

209 months

Friday 10th May 2013
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I've been contemplating doing this to the car I'm restoring but from what I'm hearing it's a bit of a nightmare to try and get every last bit of blast media out, which some believe could become a moisture trap. Not saying I've ruled it out myself but it's something to think about!

V8LM

5,528 posts

235 months

Friday 10th May 2013
quotequote all
McWigglebum4th said:
i would not sand blast a car shell

Glass blast maybe

Soda blast even better

Not sand as its too aggressive
Depends on whether you want to find out how good the chassis is.



But no, I wouldn't blast a shell.


ellis427

Original Poster:

1,653 posts

205 months

Friday 10th May 2013
quotequote all
Hmmm so very split opinions.

Sand blasting is one option as the shell is in very good condition anyway.

What options do I have? Soda blasting? What does that involve?

Also would anyone recommend an acid bath? Heard worse things about them though.

And yeah I would spend as much as it cost's to do properly. Which offers best value for money?


Thanks guys, really helping

Kitchski

6,549 posts

257 months

Friday 10th May 2013
quotequote all
I'd definitely acid-dip a shell.

ellis427

Original Poster:

1,653 posts

205 months

Friday 10th May 2013
quotequote all
What benefits does it have in relation? Also is it far more expensive?

Camaro

1,432 posts

201 months

Friday 10th May 2013
quotequote all
Kitchski said:
I'd definitely acid-dip a shell.
Could end up in a similar or worse situation acid dipping it.

At least sand blasting, the guy doing it might take it easy once he seems a panel falling apart. With acid dipping, you might not have anything left coming out of the tank! frown

mat777

10,712 posts

186 months

Friday 10th May 2013
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Get it acid dipped. No worries about blast media remaining, and its a far more gentle treatment

stevesingo

5,027 posts

248 months

Friday 10th May 2013
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I used these... http://www.surfaceprocessing.co.uk/for-cars.html#s...







And they will also e coat the shell...




That was December 2007 and it is still in one piece.


mini1380cc

2,949 posts

197 months

Friday 10th May 2013
quotequote all
I'm told that sand blasting can distort panels, leaving a wave affect across the surface. Although its cheaper than a dip, I'm told a dip is more thorough yet less aggressive.

ellis427

Original Poster:

1,653 posts

205 months

Saturday 11th May 2013
quotequote all
Thank for the replies guys very useful.

I shall look into acid bathing then, also thanks for the link.

If you don' t mind me asking how much did it cost to acid bath, and then have sprayed?


Kitchski

6,549 posts

257 months

Saturday 11th May 2013
quotequote all
Camaro said:
Could end up in a similar or worse situation acid dipping it.

At least sand blasting, the guy doing it might take it easy once he seems a panel falling apart. With acid dipping, you might not have anything left coming out of the tank! frown
I should think there would be little point saving a shell that couldn't handle the dip

jagracer

8,248 posts

262 months

Saturday 11th May 2013
quotequote all
ellis427 said:
Thank for the replies guys very useful.

I shall look into acid bathing then, also thanks for the link.

If you don' t mind me asking how much did it cost to acid bath, and then have sprayed?
A couple of years ago a MK1 Escort cost about £750, then they wanted about the same to give it an e coat dip to stop it rusting. If you want to do it properly you should then get it coated again once you've done any repairs.


Edited by jagracer on Saturday 11th May 14:26

droopsnoot

14,372 posts

268 months

Saturday 11th May 2013
quotequote all
My concern with acid dipping is - what happens if an internal section of the shell is quite bad, the outer parts around it are quite good, and the acid dip dissolves the centre part? Imagine for example an MGB, has an inner sill, centre 'castle' I think, and an outer sill, it's got a good inner and a new outer, but the castle was only just decent when the outer was fitted. Acid dip it, the outers are fine but the inner is now gone completely. How would you ever know?

I couldn't dip the car I'm working on because the structure was too bad until I'd done some of the repairs, and I've been trying to open up pretty much all the box sections just to see that there is some decent metal inside. But what do others do? Just assume that if the outers are good then the inners will be too? I could see that being good for a car that's never had any replacement panels, so I guess it depends on age.

I've heard bad things about dipping, but then a local chap has had it done (also to an M3, by coincidence) and is very happy with the job. I've also heard bad stuff about blasting, but someone who knows what they are doing should not cause damage. But blasting won't clean out inside box sections of course.

ellis427

Original Poster:

1,653 posts

205 months

Saturday 11th May 2013
quotequote all
jagracer said:
ellis427 said:
Thank for the replies guys very useful.

I shall look into acid bathing then, also thanks for the link.

If you don' t mind me asking how much did it cost to acid bath, and then have sprayed?
A couple of years ago a MK1 Escort cost about £750, then they wanted about the same to give it an e coat dip to stop it rusting. If you want to do it properly you should then get it coated again once you've done any repairs.


Edited by jagracer on Saturday 11th May 14:26
okay so looking at the best part of £2500 for acid bath, and 2 layers of e coats? sounds fairly reasonable.

I understand and also have the worries about the acid doing damage but the shell i have is very solid and no rust. However if there is rust what will it do? just dissolve that area?


Also are there any companies you guys can recommend! want to crack on with this project driving

jagracer

8,248 posts

262 months

Saturday 11th May 2013
quotequote all
ellis427 said:
okay so looking at the best part of £2500 for acid bath, and 2 layers of e coats? sounds fairly reasonable.

I understand and also have the worries about the acid doing damage but the shell i have is very solid and no rust. However if there is rust what will it do? just dissolve that area?


Also are there any companies you guys can recommend! want to crack on with this project driving
Those were the prices quoted a few years back, they couldn't actually e dip the entire body shell at the time as it was anew process to them and they didn't have a bath big enough but that was the approximate price he thought it would be. You may not even need to get it done again depending what work you have to do, ours needed a complete new floor, so you're best talking to them about it, they're the people in the link above near Birmingham.

Edited by jagracer on Saturday 11th May 20:25

100 IAN

1,101 posts

188 months

Sunday 12th May 2013
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I've heard very good things about these guys and was very impressed when i went to see them.

http://www.blast-cleaning.co.uk/index.php?menuid=3...

When i was looking at blasting vs. dipping of my Alfa shell i came to the conclusion that blasting done badly can distort the panels. Soda blasting is more 'gentle' so can be used by less experienced operators but soda is salt which is not the best material to have near bare steel!

Sand is too abrasive and although people commonly refer to 'sand' blasting the professionals call it 'media' blasting, the 'media' they use being an inert softer material less likely to damage panels. That said its still a job requiring some skill to get good results without causing unnecessary damage.

Dipping is claimed to get into every nook and cranny which media-blasting can't, which i can fully beleive, but how do you then protect all those nooks and crannies sufficiently to stop them rusting?

18x months ago when i was looking there was nowhere is the UK that could e-coat a whole bodyshell. If that has now changed, dipping may be an option but without e-coating a dipped shell i think you're just exposing every panel joint to rust

The conclusion i came to was that Media-Blasting using a suitably 'soft' media by someone experienced was the best option, but the cost of this wasn't cheap.

Best of Luck