Powder Coat or POR15?

[rgh0]

Rohan, Would page 19 be more appropriate?
db

The 6 types of polyurethane coating are listed from the bottom of page 18 to middle of page 19. POR 15 is probably a type VI but maybe a type I or II?

Type II cures with atmospheric humidity and the POR 15 literature talks about humidity making it cure harder. However type II can suffer from pin holing if to thick due to Co2 generation in the cure process which does not sound like POR 15 as the literature says it is an impervious coating and it appears to apply relatively thickly so maybe not a Type II

cheers
Rohan

[Rob P]

I have used POR15 on a number of Mini Subframes in the past and it holds up well, you really do need to use the marine Clean and prep and ready solutions prior to applying the POR15 paint though for best results.
Be careful not to get it on yourself though as it is a devil to get off and stains skin for weeks.

Powder coating on mini subframes tended to last only for a year or so before water ingress and as people have stated lifting the powder coating off in chunks.

I'm still fairly new to the Lotus scene so no major work on the Elan Chassis at present but I will be sticking to POR15 as and when the time comes for any restoration work on the Elan
I have used it on the M100 Progeron and chassis parts and again it is holding up nicely

[Galwaylotus]

I bought mine restored and was able to trace the restorer. This is what he told me was done to the (original) frame:
? Chassis soda blasted, inspected, hot galvanise sprayed, four coats of 2-part epoxy applied to chassis.

Thant sounds good to me for a car that is spending its latter life in the west of Ireland!!

[661]

My new TTR chassis has arrived.
Once the weather is better I'll get it to the blaster for a mild bead blast to remove the surface rust, then it will be POR 15 metal prep and then colour coat.

[LaikaTheDog]

Used to like powder coating. Wipe clean. Smooth finish. .. until I had to work on cars coming in for their second restoration. .. the power coat had split and made rust worse. But what was left was a nightmare to get off. .. I will never use powder coating. Awful. You would be better to leave it bare metal !!

[Davidb]

Graeme, I just got my frame back from the sand blasters and I spent quite a bit of time researching the proper process before starting painting. If the chassis is freshly sand blasted then POR 15 advises to brush the paint on directly, which is what I have done today. The surface needs to be rough but clean and freshly sand blasted metal certainly meets those requirements.

I am very impressed with POR 15 so far-it goes on very easily and flows out to eliminate brush marks. Previously I have used Imron on chassis frames but the toxicity of Imron coupled with the need to spray it makes it more more of a nuisance to use.

[pharriso]

Graeme, I just got my frame back from the sand blasters and I spent quite a bit of time researching the proper process before starting painting. If the chassis is freshly sand blasted then POR 15 advises to brush the paint on directly, which is what I have done today. The surface needs to be rough but clean and freshly sand blasted metal certainly meets those requirements.

I am very impressed with POR 15 so far-it goes on very easily and flows out to eliminate brush marks. Previously I have used Imron on chassis frames but the toxicity of Imron coupled with the need to spray it makes it more more of a nuisance to use.

Did you paint your chassis in one go? You're supposed to apply the 2nd coat within 4-5 hours but how do you turn the chassis over when it's wet?

As bilcoh suggested, I'm thinking of painting my chassis in 2 stages.

[Davidb]

Pharisso: I am doing it in two stages as well--I don't think it can be done-easily-in one go. I have painted all the areas I can reach with the chassis on stands, the right way up. I put on two coats over a period of four hours. I just checked the chassis, two hours later, and the paint has "kicked off" as they say and is pretty well dry to the touch. It is damp here today but about 12 deg celsius. I have a 220 volt shop heater keeping the chassis warm. Tomorrow I will turn it over and double coat the rest of it.

[Davidb]

An hour after the last post and the paint is dry and hard to the touch-there is not much smell anymore either...

[661]

Interesting, David.
When I spoke to Frost (UK distributer) they seemed pretty set on using the metal prep on raw metal. It would be much easier to get straight onto the painting! I'll make more enquiries.

[jeff jackson]

Hi all,
Very interesting read about powder coating. I have had loads of bits and bobs powder coated like the airbox metalwork, between the carbs and the inlet manifold and it looks like new again.
I was going to get my replacement chassis (Frame) powder coated.....until now!!
For us on this side of the pond, we can get POR15, but I have used epoxy 121 from Rust.co.uk.
http://www.rust.co.uk/buy-epoxy-mastic/p404984
A really sticky two part paint that is awesome once its applied, I have used it on my metal car restorations and works really well.
Worth considering as an alternative to PO15? About the same price I think.

Kind regards
Jeff 72+2

[englishmaninwales]

The powder coating on my Caterham chassis was falling off in large chunks with rust underneath by 15 years of age. Stripped the whole chassis frame of the PC using paint stripper, metal rubbed down by hand, Marine clean, wash, phosphate etch,wash and then hand applied POR 15 by brush. Left a smooth durable finish. I didn't bother with UV protection.
Pity I crashed it and ended up with a new long front chassis replacement that is powder coated Remaining 2/3 of the chassis that is POR coated looks good 5 years on.
Of course easier compared to the ?lan, as the frame is easily turned over with 2 people.
Suspension components were nylon coated rather than PC and very durable andchip free.

[Davidb]

EMIW: There must be a moral here somewhere!:) I am so glad I did not go with powder coating. I finished painting the chassis this afternoon and it looks luverly, apart from the runs...

[Chancer]

Englishmaninwales.

I second your comments about the powder coating on Caterhams, pre 1985 (approx) they were stove enamelled and it was a superb finish, in fact they would rust all the way through from the inside of the tubing before the coating woul detach, of course in those days the cars were used all days in all weathers and often parked outside.

Powder coated chassis for todays cosseted toys is probably acceptable but as you say the exposed components, suspension, wing and light brackets etc last about as long as a Chinese barbecue.

I had my Westfield chassis powder coated by one of the subcontractors we used and it was done in the Superior and more costly material, epoxy perhaps. I had suspension components and the roll bar Vyflexed and that was the best coating that I have ever known.

I have read some comments about powder coating over an undercoat, AFAIK thats impossible as its an electrostatic process that has to go over bare conductive metal, I also read about it being used over hot zinc spray, that is a process I use a lot but is it conductive enough for powder coat and does it stick well to it, anyone know?

I have the ultimate answer on my trailer after its second rebuild 11 years ago, out in all weathers and no peeling of the coating, but its impractical to say the least, hot zinc sprayed and then hand painted with black bitumen paint, the only paint that will adhere to non weathered galvanising, trouble is that it remains sticky for years and has no resistance to petrol, mine has rubbed through in a few places around the coupling and jockey Wheel but the zinc spray is unaffected, no rusting and its been outside in all weathers for 11 years.

Hot zinc spray is excellent for rust proofing but how to get an attractive finish over it? Powder coating perhaps?

Anyone tried it?

[pharriso]

I have read some comments about powder coating over an undercoat, AFAIK thats impossible as its an electrostatic process that has to go over bare conductive metal, I also read about it being used over hot zinc spray, that is a process I use a lot but is it conductive enough for powder coat and does it stick well to it, anyone know?

I had my radiator side plates powder coated 2 weeks ago. The powder coater (Prestige Industrial finishing of Shelton CT, who do a lot of work for Sikorsky Aircraft) recommended a "zinc rich primer" prior to the powder coat in case the part gets scratched or chipped. Here's the before & after:

Before

After.. maybe too nice?

Cost was $75 - about GBP50.