The 'E' Type Forum

I am considering powder coating the IRS on my rebuild and was looking for comments and advice. One thing that concerns me is the drive shafts and other critical areas where paint build up could be a an issue. I don't want to have to scrape it all back off again. I guess I could put the old UJ caps back in before coating? What do most do? And of course the top diff counter sunk bolts similarly

We powder coat the wishbones, frame and baseplate, the springs and the radius arms.
We don't do the halfshafts nor the fulcrum brackets as trying to remove stray plastic from the holes is a miserable experience.
The halfshafts get sandblasted, then painted with black enamel, and then we paint over the UJs once they are installed.
The pumpkin is painted in enamel.
The half shaft covers get binned.

andrewh wrote:I am considering powder coating the IRS on my rebuild and was looking for comments and advice. One thing that concerns me is the drive shafts and other critical areas where paint build up could be a an issue. I don't want to have to scrape it all back off again. I guess I could put the old UJ caps back in before coating? What do most do? And of course the top diff counter sunk bolts similarly

I did mine. I put the U/J caps back into the halfshafts and yoke, and masked off the mating surfaces on the yoke (as well as the countersinks in the top of the cage). The inner fulcrum brackets and the brake caliper brackets I had zinc plated in black. The Diff casing I hand painted with Hammerite (hand mixed to match the original reddish brown). If you are going to blast the parts yourself go to the powdercoater ahead of time and get some high temp masking tape from them first - then you can mask it yourself and know exactly who is to blame when it isn't right.

I thought that getting the shocks into the space for the bush would be a struggle, but it wasn't.

If you are going to fit a new tie plate you might want to trial fit it to the cage/diff, I had to shift a couple of the holes on my new one. Similarily, if you want to fit remote bleeders and they need holes in the cage then do them before coating.

Andrew

Such a great forum. I post before bed and when I wake the answers are there. Andrew and Andrew, thank you for your advice. I painted my first rebuild and found it chipped quite a bit. I suppose the powder coating is more durable?
I didn't know that you could get masking tape to work for PC. So do we go Gloss Black or Satin?

Satin.

The masking is as good as your powder coater. Ours sadly is a bit slack so I tend to err on the side of caution.

One go at getting plastic out of the circlip grooves was enough for me.

The slightly decreased space for the shocks is actually good; you tap them in place with a hammer and they obligingly stay put while you get the bolt in.

WRT to shocker bolts. ONLY EVER put them in from this inside of the cage so the nuts are on the outside. You will NEVER be able to remove your rear shockers otherwise.

Agree with Andrew. In addition, we nickle plate handbrake assembly, distance tubes and handbrake adjuster. We normally bin the radius arms, springs and shocks as it is not a lot more to fit new, assembled units.

I don't agree abut the springs, the available new ones are unsuitable.

abowie wrote:I don't agree abut the springs, the available new ones are unsuitable.

Why are they unsuitable? Wrong length?

Long discussion in the archives.
New springs are too long too thick and have too many turns.
Reuse your old ones.

andrewh wrote:Such a great forum. I post before bed and when I wake the answers are there. Andrew and Andrew, thank you for your advice. I painted my first rebuild and found it chipped quite a bit. I suppose the powder coating is more durable?
I didn't know that you could get masking tape to work for PC. So do we go Gloss Black or Satin?

Andrew:
The powder coaters use a special masking tape, normal masking tape won't hold up in the oven, so you need to drop by and get some tape from him. It is important that you do your own masking - the guy at the powdercoat shop won't know where to mask exactly. If you are having the powdercoater blast the parts for you then do your masking with Duck tape.

Put a fastener in every blind threaded hole, on non blind holes only thread in until the fastener just covers the threads in the hole, and a nut on the _beginning_ of every stud. The aim is
1) to be able to get the now powdercoated fastener off/out
2) get a die/tap started

Powder coat will chip, but not as easily as paint. You can wash it with a power washer and pretty much any solvent/engine soap (some coatings will soften with brake fluid).

I have my PC done at a large shop, when I take a batch he just waits until he is doing a run of black - that way I save money because he doesn't have to change colour on his line. Satin is what I would ask for.

Andrew

Thanks once again Andrew. I am thinking of painting the driver shafts and PC the rest but take on board all the advice much appreciated

Not powder coated any e type bits yet but did when I rebuilt my MG some years back. My experience is that engine bits....fine. They stay mostly dry and don't get chipped.

However. Bits underneath....complete waste of time. I powder coated all the front suspension and rear axle casing etc on the MG. As soon as it chips....and it will...water gets underneath the coat and in no time it all peels off. If and when I do my IRS it will be cleaned, wire brushed, etch primed and painted with hammerite or similar. Yes it will chip but paint is far less prone to peeling and sticks much better on sharp corners than plastic ever will. Chipped paint can be retouched... Powder coating cannot. In my humble opinion powder coating is a waste of time....unless you plan to just trailer your car to shows. Looks fabulous new but underneath a car a complete waste of time. Sorry!!! J

Not if it done to the correct standard. Its is primed prior tl final coat. If it does chip, the primer remains. Sorry!

Is powder coating not different to plastic coating? I rather thought it was . I have plenty of experience e of plastic coating peeling, usually on cheap garden tables and BBQs eats. PC such as in my Honda Rotary Mower has not deteriorated in 12 years.

Hi Andrew...just search on the net it will tell you all you need to know about it and the different types.....you do however need to find a recommended coater if you go ahead with it or you will find that if not done correctly it will peel off.. personally I went for grit blasting, zinc primer, and extreme chassis black undercoat and topcoat... Steve

Just for the record my bits were grit blasted, primed, electrostatically sprayed at high temp and looked A..mazing when new. Five years later peeling everywhere. It is sharp edges that fail first. And sorry but primer ain't water proof. It rusts under the primer and just lifts it off. And you can't re touch powder coating! Once a peel sets in that's it. You can paint. Just my experience and others may have better results. Engine bay stuff absolutely fine years later but underneath...forget it.

Considering the hassle of selecting a reputable powder coating supplier, masking with high temp tape, agreeing suitable pre-treatment (e.g. phosphate wash), arranging transport x2, lead times etc, why not just "do it yourself" in as much as spraying on a 2-pack etch primer or epoxy primer, then within overcoat interval (usually 30mins to 3 days) apply either a 2K topcoat, or a black base & 2K clear. It's easily done even with a cheapo spray gun and a small compressor. Bit of plastic sheeting to make a small booth and a carbon respirator (or fresh air mask). It's cheap, it's quick (you're done in an afternoon), you'll get satisfaction from the work, and with the 3-stage finish you'll get a coating as durable as the rest of the car.....

I know what I prefer :D

Umm. Food for thought. I always spray my black stuff on a restoration myself and have never had any problems with it but I note a few restorers are now PC the IRS so wondered if I was missing something. I reckon it's being done to speed and cheapen the process somewhat so I am beginning to think it's best to stick with the painting . I shall think on. Many thanks to everyone for the contributions as always much appreciated :D

When I had my IRS parts powder coated I too was concerned about what I'd heard re the coating flaking off. I was assured that if preparation & primer were done correctly I would not face issues. When it came back the PC had crept into a couple of areas it shouldn't have. It was rock hard & extremely difficult to file/chip/cut away so I can't imagine it's going to flake off easily. I went for the gloss on the basis that I thought it less adherent thus less road crud should stick to it. Delighted with the finish.

However the radius arms couldn't be PC'd as they already had the bushes installed so went for 2-pack. Just as pleased with this finish but doesn't resist impacts as much as the PC.

andrewh wrote:Umm. Food for thought. I always spray my black stuff on a restoration myself and have never had any problems with it but I note a few restorers are now PC the IRS so wondered if I was missing something. I reckon it's being done to speed and cheapen the process somewhat so I am beginning to think it's best to stick with the painting . I shall think on. Many thanks to everyone for the contributions as always much appreciated :D

As with every other decision, each possibility entails some compromise or risk. I haven't had or seen any problems with powder coated suspensions here in Switzerland, but that may be just as a result of the coaters using a zinc primer and a higher quality powder. There are huge differences in the powder coating powders: Most garden tools are powder coated nowadays, on some the coating lasts forever, on some it barely makes it through a single season (yes, steel quality also makes a difference, but the IRS steel is pre "Cat hair and snot alloy Steel").

As to the choice of gloss or semi gloss, your choice here is determined by what you plan to use for touch up paint. If you can get some matt powder then you can use rustoleum or hammerite, or por and matt it down to match.

Andrew