Help with powder coating

**surfer** · 7th September 2007, 11:48

Can anyone help me please? I would like to get my frame, rear mudgaurd, and electrics box powder coated.

Can anyone recommend a good powder coater for the job? I know I can look in the yellow pages but I'd rather use a firm that has done a great job for someone here and knows what they are doing with a bike frame.

Got any tips for preparing the frame? There is oil on it. I was thinking of a degreaser for this and getting it blasted prior to powder coating.

Also any general advice on this whole process of what to be aware of would be great.

Cheers everyone

**Coldrider** · 7th September 2007, 12:12

When you mean 'blasted' do you mean sand blasted, this cleans up everything and gives to coating something to adhere to.

**Disco Dan** · 7th September 2007, 12:15

Turpentine. Has so many uses. ...I get through about a litre a week... jam jar, old electric tooth brush and a big dirty bike.... *heaven*

**Coldrider** · 7th September 2007, 12:17

Forgot to mention, if you get it sandblasted do not touch the frame/parts with your bare hands as oil from your skin will transfer onto the blasted metal and cause the coating not to stick so well, if you do touch it, wipe with alcohol cleaner (no oil residue left behind like turps etc) or white spirits will do. Glad you are not doing your wheels, the heat treatment from the powder coating cooks alloy, weakening it, wheels should be laquered.

**nodrog:Me** · 7th September 2007, 12:42

most good powder coaters will arrange the prep of the parts as well, personally i would let them arrange the prep as they know the best way the parts should be prepped for the best finish.

**surfer** · 7th September 2007, 16:51

Thanks for the replies, much appreciated.

Originally Posted by Coldrider

When you mean 'blasted' do you mean sand blasted, this cleans up everything and gives to coating something to adhere to.

Yes I do.

Originally Posted by Coldrider

Forgot to mention, if you get it sandblasted do not touch the frame/parts with your bare hands as oil from your skin will transfer onto the blasted metal and cause the coating not to stick so well, if you do touch it, wipe with alcohol cleaner (no oil residue left behind like turps etc) or white spirits will do. Glad you are not doing your wheels, the heat treatment from the powder coating cooks alloy, weakening it, wheels should be laquered.

Ahh cheers for this I would never have thought of that. I'm going to tidy the wheels up myself with a two pot job of paint plus a bit of polishing for the metal. Got any tips for buffing up a nice shine apart from elbow grease and autosol?

Originally Posted by nodrog

most good powder coaters will arrange the prep of the parts as well, personally i would let them arrange the prep as they know the best way the parts should be prepped for the best finish.

Good point. So do you know of any in Auckland, preferably North Shore area?

**merv** · 7th September 2007, 17:16

Originally Posted by Coldrider

Glad you are not doing your wheels, the heat treatment from the powder coating cooks alloy, weakening it, wheels should be laquered.

Hey tell me about the lower front fork tubes for my VFR - they have got stone chipped over the years and cleaning them with the hose has blasted a bit of the old coating off. What is recommended for them because powder coating you are saying the heat treatment aint so flash. Original coating was a gun grey metallic kind of look. You've mentioned lacquer for wheels, so would similar do here and what sort of prep is necessary and what paint do you buy?

**rasty** · 7th September 2007, 22:48

Try Rainbow in Albany. Top coaters and an affinity with bikes as well

**surfer** · 8th September 2007, 18:12

Originally Posted by rasty

Try Rainbow in Albany. Top coaters and an affinity with bikes as well

Thanks, I'll give them a call.

**Sketchy_Racer** · 8th September 2007, 19:13

Originally Posted by Coldrider

Forgot to mention, if you get it sandblasted do not touch the frame/parts with your bare hands as oil from your skin will transfer onto the blasted metal and cause the coating not to stick so well, if you do touch it, wipe with alcohol cleaner (no oil residue left behind like turps etc) or white spirits will do. Glad you are not doing your wheels, the heat treatment from the powder coating cooks alloy, weakening it, wheels should be laquered.

I think people have been over this before

Im fairly sure that the out come was that the heats reached in the baking process were not hot enough to affect the structural integrity of the alloy.

BUT, that is just what I have read.

-Glen

**Crisis management** · 9th September 2007, 14:54

Aluminium alloy heat treatment.
When you make cast alloy wheels they are heat treated (after casting) to about 400 degrees (don't quote me on that number and in this case it isn't important) and then quenched (dropped) in a water bath to cool them rapidly.
The idea is that the heat treatment aligns the alloy grains (while at temperature in the oven) and the water quench "freezes" them in this alignment. This results in a strong, stiff casting.

Note: Powder coating I am a bit out of date on so feel free to correct me if these temperatures have changed!

Powder coating involves spraying a dry powder onto the wheels and then melting / fusing this coating onto the wheel by passing it thru an oven. Exterior use powder requires 200 degrees to fuse, interior use requires 160 degrees.

Soooooo, when your nice clean alloy wheel gets heated to 200 degrees in the oven to fuse the powder there is no problem, but when you pull it out of the oven and let it slowly cool down there is a bit of grain realignment and the wheel ends up a bit softer.

My experience is from Ford Motor co when we made alloy wheels in south auckland and we allowed wheels two passes thru the powder coating process (once for colour and once for clear coat) to be repeated once only. IE if a wheel got reworked for a paint defect it only had one chance at the rework.
So, after 4 passes thru the powder coating process we deemed the wheel to be softened below an acceptable standard and it was scrapped.

The point to remember is that your wheels are probably ok for one coat of powder but beyond that you may be risking softening them too much.

Laquer sounds lots better to me.

Another piece of useless info....powder coating was not waterproof (may have changed since 1990's) so powder coated steel still rusts. Check with the powder coater!

**surfer** · 10th September 2007, 12:14

Originally Posted by Crisis management

Another piece of useless info....powder coating was not waterproof (may have changed since 1990's) so powder coated steel still rusts. Check with the powder coater!

Didn't know this, cheers.

Anyone got any other recommended powder coaters/sand blasters for a motorbike frame?

**Coldrider** · 10th September 2007, 14:23

Hi Surfer
You can get a buffer to fit on an electric drill to polish the wheels, small to get into the base of the spokes.

Merv
I need to do my lower fork tubes too, I was just gunna use 'spraykote' ( i think they took the ol' VHT brand) cans from mega, could do the job for less than $30, I can't justify removing & taking the forks apart. There is a laquer primer & filler primer available. fortunately mine are satin black, but there is metallic colours available, charcoal I think.
Use heat lamp to cure harder. When done you can purchase a metre lenght of clear or coloured heat shrink tubing from an electrical supplier, cut slightly longer to length, slip it over the fork tubes like a sock, and shrink it down with a heat gun. Will stoneproof real good.

**Coldrider** · 10th September 2007, 14:35

Re powder coating wheels.
I don't see why someone would degenerate the instrinsic strenght of a wheel to save a few bucks. Do motorcyclists know more than the manufactures, design engineers and metalurgists. What when these motorcycles are sold on to innocent people and they become victims. What if the wheel has a prior certified repair done, or a backyard one.
On a motorcycle you only have two wheels, very little to gain, far too much to lose.
I only ever buy new motorcycles and this is a major reason to continue that.
Who would be prepared to sign off on such a practise.