Bicycle Mechanics - Need painting help

I'm close to being done painting my bike. I've done the colour coat, and am ready for the clear coat.
I've seen few threads and blogs about painting bikes, few of them speak about doing a quick and fine sanding job before applying the clear coat. I've done this but now my frame has a slightly dusty look to it. I've gone over the entire frame with a dry rag and then a rag soaked with bit of terpantine to get rid of oil residues and all that. There is no dust on it whatsoever!
My question is, am I good to put the clear coat on, or is the dusty appearance going to be visible even after the clear coat? My dad who's painted stuff here and there says the dusty appearance is gonna be visible through the final coat. :cry:

Any painters in here know if I'm still good or if I've gone and screwed up all my hard work?

A dusty "look" is not a problem, as long as it is not actually dust. When a base coat is sanded (w/400-1000 grit), it should have a dull look to it - even if it is a brilliant color or a metallic. The clear will bring out the flake and /or the brilliance of the color. I would not use too many chemicals before applying clear, and be sure your cloth is dust free. A well worn cotton tee works well.

If all else fails and your clear has dust in it, you can always sand the clear and re-coat. God speed, HR.

Thank You sir!
That's a big relief. I'll go over the entire bike with an old shirt once more before getting down to business again.
I will be posting the results once I'm done.

Cheers! :)

You don't say if the color is metallic or not but if it is metallic and you sanded it before clear coating chances are that you will see the sand scratches. Dupont specifically states not to sand the base before clearcoating. Doing so actually compromises adhesion. I'm not sure about other paint manufacturers. If it is a solid color chances are you will be OK going ahead and clearing. Also you should not wipe basecoat with turpentine. The oily residue can cause fisheyes in the clearcoat. A damp cloth would remove any residue and then wipe with a tack cloth. If you are using metallic and you want to be sure not to see scratches I would apply another coat of base before clearing. Good Luck

You don't say if the color is metallic or not but if it is metallic and you sanded it before clear coating chances are that you will see the sand scratches. Dupont specifically states not to sand the base before clearcoating. Doing so actually compromises adhesion. I'm not sure about other paint manufacturers. If it is a solid color chances are you will be OK going ahead and clearing. Also you should not wipe basecoat with turpentine. The oily residue can cause fisheyes in the clearcoat. A damp cloth would remove any residue and then wipe with a tack cloth. If you are using metallic and you want to be sure not to see scratches I would apply another coat of base before clearing. Good Luck


02EBZ is correct.
As long as you apply the clearcoat within the manufactures time frame there is no need to sand the base coat. If for some reason you have to sand the basecoat, ie. dirt particles, then apply another light base coat. Always follow the the directions on the product container...especially with base coat/clear coat. I painted cars for a living for over twenty years...I know what I'm talking about.

Mikey

I painted with a solid colour.
The reason I wanted to sand was because the spray gun I used wasn't the best so it left a bit of a texture to the paint. Nothing major but I could easily feel it with my hands while going over it. Also I wanted to leave the frame to dry over the week before applying the clear coat so I had to clean it and I was told that the turpentine would be fine.
Should I go over the frame with a mild dish detergent solution and then a damp rag after to clean any residue the turpentine may have left?

Since you haven't stated what paint you are usin, no one here can answer your question with 100% authority. Most paint manufacturers will spec the time between coats, or the cure time if that window is lost. Many are something like recoat within two hours or wait 48. And I agree like the other posters have said, you shouldn't sand the base coat in a base/clear paint application. If you did, you should re-base shoot it before clearcoat.

As to what to wipe it with, is it enamel or lacquer? General rule of thumb is you can use whatever you would use a the reducer for the paint, but that's not always the case. Turpentine due to it's oil base is definitely a no-no. If done in a clean place you should have had to just tack rack it and shoot the clear layer.

This from a guy that does show cars, but painting bikes just means more curves and nooks and crannies! :-(

-Roger

The paint is Dulux WetherGuard, exterior alkyd.
My clear coat however is of a different brand, I can't recall what it is. However, it seems to be for finishing woodwork. My dad said this isn't a problem, the guy at the store also said it should work on metal just as good. I'm concerned about this. Should I be?

Edit: I said I used turpentine, it actually is a paint thinner, donno if that changes much, but that's what I've been using the thin the paints and also clean the frame after sanding/handling the frame.

Wow, you shocked me with the house paint news. My backround is with painting cars and using automotive paints. I can't imagine how you will get a quality job with house paint but I would be interested to see how it comes out and how long it lasts. Good Luck

Behr makes a good 'New Drywall Primer and Sealer' latex interior paint. I would say use that as your primer - just apply it with a cheapo chip brush. For the top coat & polyurethane/varnish or shellac - I would definately use a high quality house painting brush.

Wow, you shocked me with the house paint news. My backround is with painting cars and using automotive paints. I can't imagine how you will get a quality job with house paint but I would be interested to see how it comes out and how long it lasts. Good Luck

Yea well that's what I get for sending my old man to get the paint for me. I figured he knew what he's doing. The paint stuck on quite well actually and seems very strong. I didnt have any adhesion problems or any nasty drying artifacts. I'll let you know if I have problems.

enamel house paint is fine for metalwork, like all enamel it makes a hard strong surface finish. enamel is not so good with uv fading. nor is it recommended for application of clearcoat. if you gave it a very light sand with fine paper it will be good for adhesion, although not recommended by manufacturer many people spray clear coats over the top of enamel np, and in my experience improves fade resistance. there are additives you can add to enamel to slow fade but as you have already sprayed is of no point now. for cleaning the frame before spraying wipe with perepsol or second best thinners. Do not apply turps or any cleaning solvents!! even your hands have oil and can effect the surface. Do not worry about the house paint enamel the end result will come down to technique and surface preparation. and remember the worst the job you do - the less chance of someone wanting to steal your ride!:thumb:

rustguard: I'm not too worried about fading even if it happens. The colour i've chosen is very light and pale. I used a paint thinner for wiping down the frame. At first I thought it was turpentine, but it wasn't.
I figured since this is my first paintjob i'll be fine. I wasn't intending on selling the frame, just having a clean frame. Also it's been a good learning opportunity, it's an entirely different story than reading a ton of online tutorials on painting. So next time around it'll be a lot easier. Thx for ur tips!

If I were painting it as I have a lot of boats. I would use a two part paint. I don't think the house paint is going to get hard enough. Also, I would go in steps with the sanding starting with 400 grid, 800 and end up with 1200. I would wipe it down with Acetone and then a tack cloth. Then I would put the clear coat on. Just the way I do it, good luck.

Thanks for your insight, George.
I've just applied the last clear coat on now so im basically done.
I've allowed 24 hours of dry time between the three clear coats, and the last time the clear coat dried it seemed real tough! I did a spray-can job about 7 years ago and that paint can't compare to this.