Chassis dipping and stripping
Chassis dipping and stripping
Author
Discussion

dbv8

Original Poster:

8,676 posts

249 months

Monday 14th December 2009
quotequote all
My local shotblaster reckons they can only remove damaged and flakey powdercoating from my chassis and not the good stuff.
They suggest i find somewhere to get the chassis dipped to strip.

I have to rethink my options.
Do i find somewhere maybe over 100 miles away and transport the chassis about or can i find an alternative option?
Can i get the shotblasters to remove all the damaged powdercoated areas then POR15 the bare areas and topcoat the whole chassis?
Or do i drill a couple of hundred holes, get the outriggers replaced and then send away to get dipped then galvanized?

TVR_owner

3,349 posts

220 months

Monday 14th December 2009
quotequote all
Get it properly stripped, blasted and then powder coated (if that's the finish you want).

Just make sure who ever does the coating does it immediately after blasting.

dbv8

Original Poster:

8,676 posts

249 months

Monday 14th December 2009
quotequote all
Update.
The stupid shotblasters thought it was plastic coated.
Now they say £200 to strip it.
Ive had a quote to strip and galvanize for £250+ vat so i will confirm with them this includes full stripping of the powdercoating and then get the people replacing my outriggers to start drilling holes.

Jackal83

178 posts

203 months

Monday 14th December 2009
quotequote all
Will you run the risk of the chassis warping in galv???? And have to drill a hole in all the seal on the car to lt it breath so the steel does not explode open?????

And if it goes wrong it will be a nightmare...frown massive drip marks under it... horid jaged edges..

dbv8

Original Poster:

8,676 posts

249 months

Monday 14th December 2009
quotequote all
Jackal83 said:
Will you run the risk of the chassis warping in galv????..
Yes.
This has been done and proven before.
See in the Chimaera forum the post by Saml666.
edited to add limk... http://pistonheads.co.uk/gassing/topic.asp?h=0&amp...
Lots of drilled 5mm holes and it will be fine

Edited by dbv8 on Monday 14th December 17:58

heightswitch

6,322 posts

279 months

Monday 14th December 2009
quotequote all
NO NO NO NO! DO NOT WHATEVER YOU DO HAVE YOUR CHASSIS GALVANIZED.

Numpties who galvanise railings will definitely 100% warp and twist your chassis and render it scrap.

Acid dipping OK
Light blasting OK
Aluminium hot metal spraying OK
powder coating and painting OK

NEVER GALVANIZE.

N.

TVR653X

1,042 posts

204 months

Monday 14th December 2009
quotequote all
heightswitch said:
NO NO NO NO! DO NOT WHATEVER YOU DO HAVE YOUR CHASSIS GALVANIZED.

Numpties who galvanise railings will definitely 100% warp and twist your chassis and render it scrap.

Acid dipping OK
Light blasting OK
Aluminium hot metal spraying OK
powder coating and painting OK

NEVER GALVANIZE.

N.
What makes you say this? Plenty of galvanized chassis have been done...

BliarOut

72,863 posts

268 months

Monday 14th December 2009
quotequote all
I'm assuming he means hot dipping, not a cold process.

bsdnazz

762 posts

282 months

Monday 14th December 2009
quotequote all
heightswitch said:
NO NO NO NO! DO NOT WHATEVER YOU DO HAVE YOUR CHASSIS GALVANIZED.

Numpties who galvanise railings will definitely 100% warp and twist your chassis and render it scrap.

Acid dipping OK
Light blasting OK
Aluminium hot metal spraying OK
powder coating and painting OK

NEVER GALVANIZE.

N.
There's a steady stream of people posting the results of their hot dip chassis galvanizations. I'm sure there are numpties who can warp a chassis but there are also good companies that don't.

Also, warping is muct more of a problem with sheet steel that with fabricated tube structures like a chassis.

shapeshifter

1,181 posts

251 months

Monday 14th December 2009
quotequote all
Acid stripping is the answer, had mine done, old chassis into new.

dbv8

Original Poster:

8,676 posts

249 months

Monday 14th December 2009
quotequote all
From the Pillar-Wedge website.....
'
The hot dip galvanizing process consists of 3 distinct phases

* Pre-Treatment
* Galvanizing
* Inspection

Pre-Treatment

Pre Treatment for galvanizing consists of 4 separate stages

* Inspection - Items are inspected to ensure they are safe & suitable to galvanize. This involves checking whether they are adequately vented. Surfaces are checked for signs of contamination with paint, grease, etc. as these will not be removed in the process and would cause the process to fail.
* Degreasing - Steel is immersed in a degreasing solution which removes light oil contamination.
* Pickling - Acid strips the steel surface back to clean base steel.
* Fluxing - A flux solution is applied to the steel to assist with the galvanizing reaction.

Galvanizing

Material is immersed in molten zinc at a temperature of around 450 degrees until the temperature of the work is the same as the Zinc. During this process the molten zinc reacts with the surface of the steel to form a series of zinc/iron alloys. These alloy layers protect steel from corrosion for 30-40 years and more.

As work is removed from the zinc, the zinc on its surface will begin to solidify, as this happens excess zinc is removed to ensure a smooth finish. Work is then usually transferred to a quench tank where it is cooled to allow handling.
Inspection

The galvanized steel is first visually inspected for its appearance and conformity to standard. Batches may then be non-destructively tested for coating thickness and uniformity.'

heightswitch

6,322 posts

279 months

Monday 14th December 2009
quotequote all
bsdnazz said:
heightswitch said:
NO NO NO NO! DO NOT WHATEVER YOU DO HAVE YOUR CHASSIS GALVANIZED.

Numpties who galvanise railings will definitely 100% warp and twist your chassis and render it scrap.

Acid dipping OK
Light blasting OK
Aluminium hot metal spraying OK
powder coating and painting OK

NEVER GALVANIZE.

N.
There's a steady stream of people posting the results of their hot dip chassis galvanizations. I'm sure there are numpties who can warp a chassis but there are also good companies that don't.

Also, warping is muct more of a problem with sheet steel that with fabricated tube structures like a chassis.
Good Luck.
N.

JR

14,332 posts

287 months

Monday 14th December 2009
quotequote all
As an engineer I've been thinking about this process for a while now and do wonder how much the resultant chassis movement would be. Could you please take measurements before and after to let us know? (FWIW I doubt that the shape that it returns to will be much difference but I wouldn't take the risk and do it to either of my cars. The epoxy mastic paint system, amongst others, will give a very long life of protection to the chassis without the heat distortion worry.)

GAjon

4,087 posts

242 months

Monday 14th December 2009
quotequote all
dbv8 said:
From the Pillar-Wedge website.....
'
The hot dip galvanizing process consists of 3 distinct phases

* Pre-Treatment
* Galvanizing
* Inspection

Pre-Treatment

Pre Treatment for galvanizing consists of 4 separate stages

* Inspection - Items are inspected to ensure they are safe & suitable to galvanize. This involves checking whether they are adequately vented. Surfaces are checked for signs of contamination with paint, grease, etc. as these will not be removed in the process and would cause the process to fail.
* Degreasing - Steel is immersed in a degreasing solution which removes light oil contamination.
* Pickling - Acid strips the steel surface back to clean base steel.
* Fluxing - A flux solution is applied to the steel to assist with the galvanizing reaction.

Galvanizing

Material is immersed in molten zinc at a temperature of around 450 degrees until the temperature of the work is the same as the Zinc. During this process the molten zinc reacts with the surface of the steel to form a series of zinc/iron alloys. These alloy layers protect steel from corrosion for 30-40 years and more.

As work is removed from the zinc, the zinc on its surface will begin to solidify, as this happens excess zinc is removed to ensure a smooth finish. Work is then usually transferred to a quench tank where it is cooled to allow handling.
Inspection

The galvanized steel is first visually inspected for its appearance and conformity to standard. Batches may then be non-destructively tested for coating thickness and uniformity.'
If Pillar Wedge get an order to galv 500T of structural steel to be done in a hurry, they'll land it on your chassis without even blinking.

dbv8

Original Poster:

8,676 posts

249 months

Monday 14th December 2009
quotequote all
Thats nice to know eek

Something more you want to tell us?

JR

14,332 posts

287 months

Monday 14th December 2009
quotequote all
dbv8 said:
Thats nice to know eek

Something more you want to tell us?
Your chassis would make quite a nice cushion for the structural stuff.

GAjon

4,087 posts

242 months

Monday 14th December 2009
quotequote all
I didn't mean it to come over as a horror story, just another of the perils of hot dip galvanising.
Pillar Wedge are a big outfit who will prioritise on weight, smaller galvanisers such as Roebuck Clark might take more care.
As for galvanising a chassis, I wouldn't, but there are people on here and elswhere who have, and they claim it to be a big success and theres no doubt if done correctly its a good protection.

Jackal83

178 posts

203 months

Monday 14th December 2009
quotequote all
We have sent gates and stuff away to be glaved and sometimes they come back fine other times its crap!!! i would'nt dip a chassis... they lasted this long with abit of powercoating!!!

penno

241 posts

259 months

Monday 14th December 2009
quotequote all
If Galving distorts a chassis then how come farm gates and a like that are galved don't seem to warp these are not crossed braced like a chassis.
I'm going to be getting my landrover chassis done soon. Its around £70 for 100kgs in stoke-on-trent or if you know a man in the pub then considerable less whistle

heightswitch

6,322 posts

279 months

Monday 14th December 2009
quotequote all
penno said:
If Galving distorts a chassis then how come farm gates and a like that are galved don't seem to warp these are not crossed braced like a chassis.
I'm going to be getting my landrover chassis done soon. Its around £70 for 100kgs in stoke-on-trent or if you know a man in the pub then considerable less whistle
I often find that fencing, railings and farm gates etc are made of solid section or ductile 5-6mm thick wall tube.

Jon says it all above. There are some ( a very few)galvanisers who may take a lot of time, carefully drill and prep before dipping. They may dip carefully and evenly and correctly immerse the item very slowly for specified times prior to careful extraction, clearing excess etc etc.

A Land rover chassis is essentially quite a bit bigger and a bit heavier (not unlike a farm gate) than a thin wall tube TVR chassis. it also has lots of 1" holes all over its 2 main sections which allow the molten metal and hot gasses etc to dissipate evenly as the chassis is immersed

The reality with galvanizing companies is that lots of heavy builders type metal is done in a very heavy builder type way quickly to price and en masse. I would have it as a guess and I may be stereo typing Barrow here That "delicate" wouldn't be the usual type of galvanizing carried out in that locale

At the end of the day. Its your car, do what you like!

For a while It was a fad of TR6 restorers to galv their chassis, I watched a few get done. it was common place to watch 2 men manhandle the chassis in and 4 to take it away afterwards!!

As i said. it may be perfectly fine but why take the chance.

My chassis is 40 years old for the first 25 it only had a coat of chassis black. How long do you want them to last??