Painting bike help

[ephect]

I'm painting a bike which appears to be possibly powder coated. The coating turned dusty, so I've been hitting it with a wire wheel to take the dusk off and clean up some rust.

Been doing some research on priming, and this is where I need some help.

I know I can etch prime bare metal (cleaned rust) but I've read it won't stick to paint well. I'm not going to strip the coating off it all. How bad will it be if I half etch it then prime the rest?

Thanks in advance

 

[losh1971]

I possibly wouldn't worry about etch on a bike frame. Pretty sure I just primed mine on the RD then used a baked enamel over that.

 

[ephect]

Don't I need etch to treat and seal the rusted areas?

 

[Drawnnite]

So im going through a similar thing at the moment with a frame (bicycle though)
Do you know if its chromoly?
If its cromo you could go see the guys at ADA Powdercoating and they can bake the powder off.
Otherwise you can chemically get it off but have to be careful with the tubes to not let the chemicals sit in there.

As for the repainting, whats your plan with it?
If its only some areas youre doing fully, do some full prep if you have the time.
Then just scuff up the other areas and prep them as you would normally.

Did something similar in the bay of the VS. Fully wire wheeled back to bare in a few spots and did all the etch priming before layering some rattle can paints.
The other areas I just scuffed up and either hit it with the rattle can or gave it a quick prime and then rattled it.

 

[Deuce]

Have a look at the POR-15 range of products. They might have something to help.

 

[ephect]

Thanks guys, I want to do a full paint job on it. No idea what type but the frame looks iron, from cleaning the rust.

I'll etch tomorrow on the bare spots and continue scuffing it up, and see how it goes. I'll check POR-15 for something.

 

[Drawnnite]

Hows this going Phect?

I spoke with the guy thats going to do the paint on my frame (Its purely a clear) about how i need to prep it to get to him.
Scotchbrite and a prepwash (Wax and grease) to clean up the bit of rust thats showing.
Then when I hand it to him he has some fancy cleaner thatll prep it straight for the clear paint (some kind of cleaner/primer i think)

Possibly prep it the same way to then prime and paint for you?

 

[ephect]

Hey Drawn
Thanks for checking in. I've sanded and wire wheels some more, I bought some etch and primer for the frame and that's as far as I've gotten.

Need more clean up on the frame before I can start on paint. I need some scotchbriet pads and wax grease remover too, thanks for the info.

Weekdays and weekends I've spent at family's helping round their house so I haven't had much time to continue on it.

I'll post some updates when I get to it.

 

[hademall]

This all brings back memories. My very first job after leaving school was as an apprentice stove enameler.
They specialised in bicycle and motorcycle frames and motorcycle petrol tanks.
Three months of wet and dry sanding of motorcycle petrol tanks and a c@#t of a second year apprentice to work alongside, who hated me because the bosses pointed out my work was better than his, was enough for me to move on to bigger and better things

 

[Hole Denn]

Yes etch will cause issues on painted surfaces.
Etch is a sealer not a primer to prevent moisture getting to bare metal, really used for alloys. Epoxy [sealer like etch] is for steel.

For your application, epoxy coat just the areas of rust repair [if deep repairs body fill or spray more coats] sand back areas, then scotch brite rest of old paint, then use a proper primer over the whole frame followed by a sand to be ready for paint colour.