Powder Coating

[F355GTS]

My 7 has been used by the previous owner as an everyday car so had been used in all weathers. It is evident that some of the powder coating has broken down and allowed surface rust to appear

 

What is the best treatment, does anybody know a Company that will strip the old powder coat off, treat the rust and re-finish?

[russb]

Which parts of the car have the problem ???

 

Russ

[F355GTS]

Russ

 

Certainly the front x frame and the rear bar with the tow hook, also the two bars at the rear going up to the centre (A frame?)

 

I'm getting a trailer on Monday so will be able to see more once it's on there

[Morls]

Arch motors can do it, mine's going in next week.

 

Try 01480459661 and ask for Bruce.

 

Mark

[F355GTS]

Mark

 

Whereabouts in the Country are they?

[Graham Perry]

Just had all my rear arms and De-dion and various other parts re-coated by Ex-cel at Mildenhall (01638) 510993. Cost about £50. They insisted that the parts arrived pre-sand blasted. It is vital that this is done in the previous 24 hours and that no fingerprints are on the metal as this will encourage rust to form under the coating. Ex-cel use an external process called auto 2000 invented by Ford and Du Pont, and it should last about 8 years.

 

I took them some Caterham parts that had the Caterham coating on for comparison. Suffice to say they were not impressed. Apparently the process used by Caterhams is mainly for interior use or occasional external use, and no obvious protective Zinc coating is applied before the powder.

 

Edited by - Graham Perry on 10 Mar 2002 07:18:59

[Chelspeed]

How old were the Caterham parts?

 

Arch do most if not all of Caterham's powder coating. About 9 years ago they used to do a cheap process 'cos Caterham were pushing them to do it as cheap as possible. About 5 years ago Caterham were getting so much stick about the quality of the powder coating on the chassis that they backed off and accepted Arch's recommendations to do something better. I think phosphate dipping comes intothe new process but have no idea whether this is zinc based or what.

 

So if you Caterham is the same vintage as mine, 1993 chassis, the powder coating will be poor. If it's less than 5 years old it should be much better.

 

Re powder coating components is easy, wishbones, A frames etc, anyone should be able to do this. Re powder coating chassis bits is a lot more involved, complete strip down, ally panels off, blast chassis, phosphate dip, re powder coat, new ally panels, repaint. I'd only trust Arch to do this. Had mine done this winter and it's superb.

[Graham Perry]

The parts I showed them were only about 5 years old. The guys that did mine said they had been done in phosphate, which they said (in their view) was internal quality . They do the phosphate process themselves, but said it would not be a long term proposition for car parts. So I went for the zinc coated option which was more expensive.

 

On my car the chassis has been fine, even after 12 years there is no rust (I peeled back some panels for a look) but the ancillary components seem to be the ones that need a higher quality coating. I found the whole subject really quite interesting (sad man)

 

Edited by - Graham Perry on 10 Mar 2002 08:28:44

[Robster]

My car is just over 3 years old, and the 'powder coating' is peeling in several places, showing rust underneath. I know that it was powder coated over the rust because if you wire brush 'good' powdercoat the metal underneath has still got rust on it. The standard is dreadful..to be honest it looks like it was painted not powder coated.

[Graham Perry]

I have now had a chance to check my notes that I made at the time. There is apparently two kinds of Phosphate pre coat. Iron Phosphate and Zinc Phosphate. The Zinc Phosphate being apparently better for exterior use. The Caterham bits I had checked over were, it would appear iron phosphate coated, or had no pre coating at all. It is easy to tell which kind of pre-coat the parts have had. If parts have had a zinc pre-coat when you scratch some coating away there is a grey undercoat that looks just like galvanising.

[millsn]

Zinc phosphate is a goldy yellow colour. A zinc coat would show as grey under the paint of a car (typical hatchbacks and roadcars).

 

It's been a while, but I recall that the zinc phospate is used to provide a good key to the stel surface. I don't think it provides any sacrifical benefit. What it probably does do is reduce the surface energy under the paint. I had my front suspension bits zinc phosphated and then undercoated, then painted with matt underbonnet paint (black) and its still looking fantastic. I aoided powder coat as it doesn't tend to be too resilient (stone chips). Under bonnet paint has been designed to be resilient to chipping.

 

My coating + shotblasting was was done by a company somewhere near Swindon (further south down the M4 if I recall).It's not cheap to get done if you only have a few bits to do as you get charged all the setup whether 2 or 7 bits.

I got a local bodyshop to do the painting.

 

Nigel Mills - 2.0 Zetec carbs

 

Edited by - millsn on 10 Mar 2002 23:35:24

[dogvet]

Apart from chassis itself there is a place in Leek (Staffs) that will nylon coat wishbones ect, much more robust than powder coating.

[Morls]

F355GTS,

Arch are in Huntingdon, Cambridgeshire.

I'm sure the process now used at Arch is powder coat over Zinc Phosphate.

Plenty Wayoyl over the top should help too.

 

Mark