Magnesium alloy repaint/coating - Page 2 - Porsche General - PistonHeads UK

I know magnesium alloys are supposed to be difficult to repaint/coat but has anyone successfully had a wheel done?

Yes ... but where are you based ? I am near York ...

Thanks, I'm in the South East but assume I could post the wheel.

http://www.tpcs-magnesium-refurbs.co.uk/

Jamie Summers said: http://www.tpcs-magnesium-refurbs.co.uk/ Thanks for that, I’d heard good things but wasn’t sure from the website if they were still in business. Any personal experiences with them?

Ian Jemmison in York is good ... he is also a specialist in repairing mag wheels having had a long experience with Minilites ...

keepup said: Thanks for that, I’d heard good things but wasn’t sure from the website if they were still in business. Any personal experiences with them? Yes, I used them to refurb the mags on my 964 RS. However, that was 10 years ago ! At that point they were really the only people in the South of the country who appeared to refurb magnesium properly. The finish was good and lasted well, however the colour was a little darker than the factory Porsche silver. Ultimately before I sold the car I had the wheels sanded back and wet-painted the correct colour, but that is not a criticism of TPCS. I am sure their processes and finishes will have evolved over the years since then.......

I’ve used Diamond styling in Sevenoaks several times for notoriously delicate 964RS wheels and the finish has always lasted well. Can’t vouch for the colour with certainty but they look fine to me. Ian

Diamond Styling may well produce a good finish on the wheels, but I don't think they treat magnesium any differently to any other metal. There are specific treatments that mag wheels need, supposedly eg crack testing and chromate treating that most refurbishers won't do.

Jamie Summers said: Yes, I used them to refurb the mags on my 964 RS. However, that was 10 years ago ! At that point they were really the only people in the South of the country who appeared to refurb magnesium properly. The finish was good and lasted well, however the colour was a little darker than the factory Porsche silver. Ultimately before I sold the car I had the wheels sanded back and wet-painted the correct colour, but that is not a criticism of TPCS. I am sure their processes and finishes will have evolved over the years since then....... Thanks. They seemed very knowledgeable but can only do up to 19” wheels unfortunately.

Jamie Summers said: Yes, I used them to refurb the mags on my 964 RS. However, that was 10 years ago ! At that point they were really the only people in the South of the country who appeared to refurb magnesium properly. The finish was good and lasted well, however the colour was a little darker than the factory Porsche silver. Ultimately before I sold the car I had the wheels sanded back and wet-painted the correct colour, but that is not a criticism of TPCS. I am sure their processes and finishes will have evolved over the years since then....... Read their T&C’s, I bet you they haven’t … I used them roughly 10-12 years ago to do my 964 RS wheels. All in all the process took nearly six months, and was a complete clusterf*ck. When I finally went to collect the wheels I was horrified at the end result. The finish wasn’t so much “orange peel” as “surface of the moon”, and as for the “close to the correct silver” the colour was nothing of the sort. I was so fed up with them, I decided to cut my losses and pay up, rather than prolong the agony of dealing with them any further. The first thing I did then was head to a body shop and have the wheels dry flatted and filled (with special instructions not to break through the chromate layer beneath the powder coat lacquer and paint) before being wet sprayed in the correct colour, then lacquered. Sound familiar… ?? The proprietor of the company alleged to have worked for Dymag before they went into liquidation. I was less than convinced … I’m surprised the company is still trading, but having read their T&C’s, and judging by the many caveats and exclusions in those T&C’s, I’d hazard a guess it’s the same individual running the show. I spoke to a magnesium foundry (Creasey Castings) about having some wheels cast 3-4 years ago. I’d suggest giving them a call and finding out who they’d recommend for re-finishing magnesium wheels. Edited by Slippydiff on Thursday 4th April 00:25

Slippydiff said: Jamie Summers said: Yes, I used them to refurb the mags on my 964 RS. However, that was 10 years ago ! At that point they were really the only people in the South of the country who appeared to refurb magnesium properly. The finish was good and lasted well, however the colour was a little darker than the factory Porsche silver. Ultimately before I sold the car I had the wheels sanded back and wet-painted the correct colour, but that is not a criticism of TPCS. I am sure their processes and finishes will have evolved over the years since then....... Read their T&C’s, I bet you they haven’t … I used them roughly 10-12 years ago to do my 964 RS wheels. All in all the process took nearly six months, and was a complete clusterf*ck. When I finally went to collect the wheels I was horrified at the end result. The finish wasn’t so much “orange peel” as “surface of the moon”, and as for the “close to the correct silver” the colour was nothing of the sort. I was so fed up with them, I decided to cut my losses and pay up, rather than prolong the agony of dealing with them any further. The first thing I did then was head to a body shop and have the wheels dry flatted and filled (with special instructions not to break through the chromate layer beneath the powder coat lacquer and paint) before being wet sprayed in the correct colour, then lacquered. Sound familiar… ?? The proprietor of the company alleged to have worked for Dymag before they went into liquidation. I was less than convinced … I’m surprised the company is still trading, but having read their T&C’s, and judging by the many caveats and exclusions in those T&C’s, I’d hazard a guess it’s the same individual running the show. I spoke to a magnesium foundry (Creasey Castings) about having some wheels cast 3-4 years ago. I’d suggest giving them a call and finding out who they’d recommend for re-finishing magnesium wheels. Edited by Slippydiff on Thursday 4th April 00:25 I also contacted Creasey Castings at the time I had a 964RS ... I had had three of different specs with multiple sets of wheels ... including one which had been acid dipped and had a "cratered" surface. Clearly the wheels had tried to dissolve themselves ... They were willing to manufacture a "replica" Cup1 shaped wheel (there is already a replica version in Aluminium that has a slightly tighter radius of the spoke shape) ... but required to manufacture ten sets at a price of around £3000 per set. Original sets could be bought at the time for around £5000 and the replicas would always have been replicas, so it was information that I held in mind in-case it was ever needed. This was a time when you could get clever stuff done ... almost bespoke, I wonder if somebody wanted replica Weissach type mags, what would happen ?

ChrisW. said: I also contacted Creasey Castings at the time I had a 964RS ... I had had three of different specs with multiple sets of wheels ... including one which had been acid dipped and had a "cratered" surface. Clearly the wheels had tried to dissolve themselves ... They were willing to manufacture a "replica" Cup1 shaped wheel (there is already a replica version in Aluminium that has a slightly tighter radius of the spoke shape) ... but required to manufacture ten sets at a price of around £3000 per set. Original sets could be bought at the time for around £5000 and the replicas would always have been replicas, so it was information that I held in mind in-case it was ever needed. This was a time when you could get clever stuff done ... almost bespoke, I wonder if somebody wanted replica Weissach type mags, what would happen ? Regrettably Chris, the 964 RS mags were produced using old production techniques, they were made from a magnesium alloy which whilst it contained magnesium (no sh*t Sherlock) it wasn’t a particularly high percentage, so whilst they were lighter than the “standard” aluminium versions, they weren’t that light. Part of the Subaru Impreza WRC car spares package I had, was a set of OZ forged magnesium wheels in 8 x 18” size. I estimate those wheels weighed no more than 6kg each. Meanwhile the Speedline magnesium wheels of the same size weighed at least 10-12kgs each. They were strong and durable (though they did crack) but would last many events and much abuse, but the OZ’s were allegedly just as strong despite being half the weight. If you want a set of replica type Weissach mags, you wouldn’t have them cast, they’d be machined from billet. I’ve PM’ed you details …

Slippydiff said: Read their T&C’s, I bet you they haven’t … I used them roughly 10-12 years ago to do my 964 RS wheels. All in all the process took nearly six months, and was a complete clusterf*ck. When I finally went to collect the wheels I was horrified at the end result. The finish wasn’t so much “orange peel” as “surface of the moon”, and as for the “close to the correct silver” the colour was nothing of the sort. I was so fed up with them, I decided to cut my losses and pay up, rather than prolong the agony of dealing with them any further. The first thing I did then was head to a body shop and have the wheels dry flatted and filled (with special instructions not to break through the chromate layer beneath the powder coat lacquer and paint) before being wet sprayed in the correct colour, then lacquered. Sound familiar… ?? The proprietor of the company alleged to have worked for Dymag before they went into liquidation. I was less than convinced … I’m surprised the company is still trading, but having read their T&C’s, and judging by the many caveats and exclusions in those T&C’s, I’d hazard a guess it’s the same individual running the show. I spoke to a magnesium foundry (Creasey Castings) about having some wheels cast 3-4 years ago. I’d suggest giving them a call and finding out who they’d recommend for re-finishing magnesium wheels. Edited by Slippydiff on Thursday 4th April 00:25 Wow, yes that sounds like it didn't go well, Slippy. My own experience wasn't that poor. I accepted the compromise on finish colour for the supposed "correct" processes prior to finishing. Perhaps I should have been fussier !

"If you want a set of replica type Weissach mags, you wouldn’t have them cast, they’d be machined from billet. I’ve PM’ed you details …" Thanks ! The power of CNC ...

ChrisW. said: "If you want a set of replica type Weissach mags, you wouldn’t have them cast, they’d be machined from billet. I’ve PM’ed you details …" Thanks ! The power of CNC ... Oh yeahh

Bit of a thread bump, has anyone had any success at changing the colour of modern Porsche magnesium wheels?

Yes RPM had mine done, change from black to Neodyme.

Snowy999 said: Yes RPM had mine done, change from black to Neodyme. Was it much of an involved process? Or a run down a repaint?

I don’t know anything about magnesium wheels but when looking at a car that had had the wheel colour changed I found this PH post from 2009. It was a significant factor in my decision not to proceed. Quote from thread below, I tried to include the hyperlink but for some reason it doesn't seem to work: “Ok its an old post.. but just to help.. I refurb wheels, have done for a long time now, magnesium wheels are a complete bind.. and there's no easy answer, a lot of companys won't touch them and with good cause. magnesium as we all know is very unstable and oxidises very repidly when in contact with air/ water/ salt/ acids.. the process to redo them is not quite as straight forward as acid strip etch prime and powdercoat!! firstly yes you have to be VERY wary of acid stripping, it has to de done, however the timing is critical.. stripping acid will not only etch magnesium badly, but will also soak into the metals pores, they have to be bathed and bathed and bathed and soaked in alkaline solution before the next stage! bead blasting, this has to be done at a low pressure as magnesium is a soft and easily damaged metal, also the risk of blasting any residues deep into the porus structure of the wheel is an issue.. after the blasting stage the true extent of corrosion is VERY evident, particularly where wheel weights have been attached.. I have seen 50% + of the actual stock completely gone where the weights have been!!, the other prime damge area is where the brake disc sits, you tend to get 2 big grooves where the brake dust has been thrown out from the pads on either side of the disc, I'v seen this so bad before that its almost rotted the wheel into two pieces!!.. at this stage you have to decide if the wheel is even safe anymore.. next comes a process called out gassing.. most wheel restorers wont even know about this and wonder why when they paint the wheels big air bubbles appear.. magnesium creates gas.. deep in the pores.. when sealed in it will build up and pop up big air blisters.. the answer is to heat them, allow them to cool and paint them immediately!!.. this will 99% stop the problem.. corrosion removed and structural integrity ascertained you then etch prime, high build prime, and paint either with powdercoat (cheap and in my opinion not recomended for mag) or a good 2k base and clear.. job done.. problem is that even the slightest contamination, or chip or scuff will set the mag off again.. basically mags are an ongoing problem and to my best knowledge cannot ever be gauranteed to last problem free for years.. so there you are.. the (I think) definitive answer about mag wheels.. personally I hate doing them, I mainly do ferrari ones and maserati, chromadora's and campagnolo's, and frankly the results can be dissapointing, as even though structurally sound the end result invariably shows some level of deep pitting.. steve grindnshine.co.uk”

I heard that there was a chromate primer that helped to stabilise the wheels prior to re-finishing them ? Note : I actually popped in to see Ian Jemmison this morning ... I had a badly dented wheel rim which my tyre fitter found whilst removing the old tyre and needed it straightening ... since driving a car on three wheels is rather hard to do. This was dropped in at 11.00am and picked up at 12.00 ish ... straightened, new tyre fitted and balanced ... thank you Ian, you saved me ! This gave me the chance to ask about the chromate primer ... no longer permitted due to its toxicity. But the key is to heat and throughly dry porous mag wheels and then use a modern powder primer whilst still hot and dry ... to seal them. There is very little that Ian can't repair ... only broken spokes which shrink back after welding and re-stress / break themselves !! A class act Edited by ChrisW. on Monday 4th August 21:49

Updated !

ChrisW. said: I heard that there was a chromate primer that helped to stabilise the wheels prior to re-finishing them ? Note : I actually popped in to see Ian Jemmison this morning ... I had a badly dented wheel rim which my tyre fitter found whilst removing the old tyre and needed it straightening ... since driving a car on three wheels is rather hard to do. This was dropped in at 11.00am and picked up at 12.00 ish ... straightened, new tyre fitted and balanced ... thank you Ian, you saved me ! This gave me the chance to ask about the chromate primer ... no longer permitted due to its toxicity. But the key is to heat and throughly dry porous mag wheels and then use a modern powder primer whilst still hot and dry ... to seal them. There is very little that Ian can't repair ... only broken spokes which shrink back after welding and re-stress / break themselves !! A class act Edited by ChrisW. on Monday 4th August 21:49 Just had a set of CGT magnesium wheels refurbed by Ian Jemmison (and his son Ben) superb job, and very reasonably priced. Edited by 993rsr on Friday 10th July 17:07