Chassis refurbishment

[Rissy]

I've been thinking a lot about chassis refurbishment again lately (I go through notions now and then)

I'm aware that some people are pro galvanising, and some are against.

I'm also aware that some are pro powder coating, and some are against.

I'm sort of sitting on the fence a bit, but leaning away from galvanising (due to warping issue associated with the heat of the process involved)

I'm also sorting of leaning away from powder coating after talking to many people and companies about the application of powder coating for chassis protection. For instance, the TVR guys have had bad experience with powder coating their tubular chassis and are recommending not to go that route.

Anyhow, my latest discovery is a company called "PRO-STRIP". They're based in Nottinghamshire.

Here's their website: http://www.prostrip.co.uk

I talked to one of their representatives for some time, and have to say I'm feeling quite positive about their processes and products for application on a DeLorean chassis. I talked to the guy for some time about them doing the stripping process with their products and then protecting the chassis with their expoxy coating. This coating (represented as the black finish on the mustang below) is thicker than paint, but not as thick as the original epoxy used on our frames. Once this stuff has been applied, you can then have the chassis painted any colour you want, if you're not happy leaving it as the black finish, but it has to be traditional automotive paint as powder coating won't work once this layer is on.

So my question here is: what are people's thoughts on this solution? And also, has anyone got any personal experience of having this company do anything for them already?

[Chris Williams]

If it were me, and my opinion only I would go with galvanising using a company that has experience in doing DeLorean frames. Do it once and do it right IMHO 8)
Chris

[Rich Hanlon]

I know Practical Classics have often recommended ProStrip for their various projects over the years...

[Dan Willis]

I'd be happy with that process. They clearly know their trade. Did they give you any idea on costs?

That's my point of pain next - where, when and how much. Logistics is the problem - getting the frame to the right place and then home. I'd rather it was rolling but that means more work....

[Rissy]

That's intetesting Rich, thanks.

Dan: what the guy told me was that they do the stripping process back to the bare metal. At this point you're called in to inspect the frame and do a self assessment of whether you want any cutting out and welding done to replace overly corroded parts etc. They don't do the welding themselves, but they can assist you in getting it done. That would be an extra cost. For the stripping process, I'm sure the guy said for a DeLorean frame you'd be looking at roughly £500.

Then once that's done, it's on to the coating. He said a micron thickness value to me which I can't remember now, but he said in terms of thickness against spray paint, it's thicker. The black epoxy stuff they can put on for you is marine certificated. He said to me that as long as the coating wasn't damaged in any way, you could dump the chassis into sea water and leave it, and no harm would come to the chassis underneath.

For this marine certificated black epoxy coating, he said, once again, for a DeLorean chassis, something in the region of £375.

So roughly £875 not including additional costs for welding repair work. Both the stripping and the coating processes are dipped processes (the coating process is a hot dip, but I can't remember about the stripping dip, if it's hot or cold), which is one of the things I liked. Powder coating is a spray on job as a comparison.

He then went on to say that you can then take the frame to someone else for them to paint up to whatever colour you wished, using any type of paint you wished, and that it would be fine on top of their epoxy coating. No reactions or whatever. Once again, that would be additional cost of however much.

The last thing he said, which I think is a pretty standard idea these days anyway, is that with the type of box chassis as the DeLorean has, he would recommend spraying all of the insides with waxoyl to give it that extra protection.

So this is all the information I discussed with him.

I liked the sounds of this approach myself.

[Dan Willis]

Interesting. I doubt mine needs much (he says) but until it's off the car, that's me being hopeful. It looks great underneath, except for the crush zone at the front where some expoxy has come off (looks like some light scuffing has done it).

Pricing wise, add another bit for whatever needs doing... I reckon that's pretty good. I could budget for that and make it a fairly quick turnaround.

Thanks for the info!

[Chris Williams]

Indeed, I'm sure it's a good process, as Rich wrote I'm often reading about it in Practical Classics as well. How does the price compare to getting a chassis dipped & galvanised?
Chris

[stunned_monkey]

Rissy Wrote:I'm sort of sitting on the fence a bit, but leaning away from galvanising (due to warping issue associated with the heat of the process involved)

There are a lot of Galvanised DeLoreans running around now. None ever presented warping issues that affected chassis geometry. Though you do get localised warping of larger flat areas, eg along the sides of the backbone.

Don't forget that the DeLorean chassis is effectively a modified Esprit chassis, and Lotus galvanised all Esprit chassis for most of its production.

Quote:I'm also sorting of leaning away from powder coating after talking to many people and companies about the application of powder coating for chassis protection. For instance, the TVR guys have had bad experience with powder coating their tubular chassis and are recommending not to go that route.

Rubbish. TVR themselves did a piss-poor job of powdercoating them when new and Cerberas around 1999-2000 are especially prone to chassis problems due to the powdercoat coming off. I researched this heavily before buying mine with the express intention of doing a chassis refurb in the coming years. Mine is currently healthy due to dilligent application of waxoyl by its previous owners.

What people are doing with them now is stripping them back and doing a decent job of re-powdercoating after a zinc-rich spray is applied. There's a very good Wheeler Dealers on the Cerbera where you can see all this taking place. Personally I'd go with nylon as a more robust if more expensive and less colourful coating.

https://www.youtube.com/watch?v=owjxF1eF-YQ

http://www.willowsportscars.co.uk/cerbe ... ation.html



So I'm glad you've brought up TVR as a reference because unlike the DeLorean, I would NOT recommend hot-dip galavnising for the TVR chassis.

Why?

Because it's a sealed tubular structure. It can't rust from the inside out because water has no way of getting into the tubes in the first place. Any sealed in at the time of manufacture will have long since been spent in the small amount of surface corrosion it would have caused (think of the DeLorean's rear control arms for a similar sealed tubular structure). TVRs rust from the outside in, DeLoreans rust from the inside out (brake fluid damage excepted)

Quote:The last thing he said, which I think is a pretty standard idea these days anyway, is that with the type of box chassis as the DeLorean has, he would recommend spraying all of the insides with waxoyl to give it that extra protection.

The DeLorean chassis was designed to be dipped. Whatever you do to protect it after it has been stripped, you must ensure to protect the inner surfaces as well as the outer, and no powerdercoating or waxoyl can guarantee this because you can't see in there, or even get in there to apply (eg the triangular tubular sections either side/above the fuel tank). And although one might suggest the tubes be sealed, I'd argue that this is impractical - eg the "tunnel" under and either side of the engine? Not "tubular" in the conventional sense.

Late DeLorean chassis received a layer of waxoyl-type stuff when new, and those chassis rust worse than standard ones.

I have used both Surface Processing in Dudley, and Prostrip to clean epoxy off. SP is the better but more expensive service because the epoxy is chemically dissolved and washed off. Prostrip heat the chassis up and burn it off (scared of warping?) which leaves quite a lot of ash behind, as we discovered when subsequently opening up some of the boxed areas for repair - this won't be pretty once galvanised.

Galvanising and powdercoating all the way.

[Dan Willis]

Lovely post Martin, I'm "dip" all the way, so my only issue is finding someone local to do it!