New GS1100 G Restoration Project. Rebuilding my Dad's bike

[psyguy]

Too pretty!

[althomas101]

Definitely powdercoat, as brake cleaner and brake fluid eat everything else I've tried. That Cad plating looks great!

[londonboards]

Day 305 Items Sent to Powder Coating

Finally got around to getting all the bits together for powder coating.

See: My GS1100G Blog - Items Sent to Powder Coating

Of course the frame goes:



main stand



and a whole bunch of other bits:





The powder coater said he would not do the brake calipers as the preparation process (including some sort of blasting) and the necessity to mask off the cylinders was too problematic. So looks like I have to do some more practice with the VHT paint. At least the satin finish I have requested is near enough the same as the caliper paint so no one should notice the difference.

[tatu]

Cad plating looks good!, is that an asbestos blanket you got there?

[Big T]

VHT makes a caliper paint that's satin black, however, your problem seem to be the lack of a good clean surface

I'd ask the powder coater if he'd blast them, or do a chemical strip

http://www.vhtpaint.com/products/caliperpaint/

[londonboards]

Nah - just an old bit of carpet.

[londonboards]

Big T - thanks for that. I think you are right. My preparation is at fault. I will soon be getting an Ultrasonic cleaner and that should help.

Greetings

[londonboards]

Still getting paint problems.

Help me out here guys. The powder coaters said they wouldn't paint them so I had another go myself and it still bubbled up:

See my GS1100G Blog - Caliper Painting Problem

I ultrasonically cleaned them as well this time round.

Here they are painted:





and then after curing:





I think it is oxidation in those areas. I either need to vapour blast them first or bake them in the oven to make sure the oxidation is not holding any moisture. What do you think?

Greetings

[Agemax]

they are reacting with something. get them dipped in an acid bath.

[londonboards]

I've got some Brick Acid which I think is 18% hydrochloric. Will that do? Or where do I find some who can dip them for me?

[Paul]

I have no experience, but I think I read somewhere paint should be cured in steps increasing the heat each time? or possibly it says 200f and youre cooking 200c ?

[Agemax]

might be ok, i had a load of stuff dipped at a local speedy strip once. they do anything from wooden doors to wrought iron gates. only charged me a couple of quid to soak the parts for an hour. came out like brand new

[psyguy]

I have no experience, but I think I read somewhere paint should be cured in steps

ditto on this one. i had the same problem

i think you have too much paint on vs curing time / temperature.

either apply thinner coats of paint and bake after each one OR

apply as much paint as you have done - that's quite a thick coating you have there - then leave to dry for a few days before baking. when you do bake it, do it on a lower temp but over longer time

good luck

[Charlie G]

My first thought was your paint was too thick. Multipile thin coats is better. Mind you I'm not an expert. I'd use a solvent based product before I use acid to clean. I'd fear etching the machined areas.

cg

[Kiwi Canuck]

Paint

I use a degreaser (simple Green) and a scrubbing brush, then wash in very hot water, air dry with compressed air and then blow dry till all moisture is gone and paint while it's still warm.
I use VHT Caliper Paint Satin Finish and cure at 200F for 1 hour per the instructions.

So far it's worked well, here's the rear brake caliper as a sample of what it looks like.