After Sandblast Sand or No Sand?

[Redneck]

Okay my question is if I sandblast a piece, should I then smooth it down with a wire wheel or sand paper or just go straight primer and do all my sanding on the primer? Keep in mind all my paint comes from a rattle can at this point. Granted all i use is duplicolor but it is still rattle can. And to add on to this question. I am going to paint the steering stem head off my parts bike and replace the one I have on the running bike, does baking the rattle can paint do any good or is it only certain types of paints that baking is effective on? Inquiring mind want to know. Thanks ahead of time.

Paul

[Nessism]

Straight to paint. Baking speeds the cure but unless you are talking about high temp engine paints and the like, that's all it does when it comes to common rattle can paints.

[posplayr]

Okay my question is if I sandblast a piece, should I then smooth it down with a wire wheel or sand paper or just go straight primer and do all my sanding on the primer? Keep in mind all my paint comes from a rattle can at this point. Granted all i use is duplicolor but it is still rattle can. And to add on to this question. I am going to paint the steering stem head off my parts bike and replace the one I have on the running bike, does baking the rattle can paint do any good or is it only certain types of paints that baking is effective on? Inquiring mind want to know. Thanks ahead of time.

Paul

if you sand blast the only thing i would do is blow it off with compressed air; do not wire wheel or anything else to contaminate the finish.

However, You could wash it down with some iorn-Phosphate primer as it will treat the metal improving rust inhibiting.

http://www.caswellplating.com/powder/pcprimer.html

Zinc-phosphate is even better and that can be had from Por-15

http://www.stoprust.net/POR-15-METAL-READY-Quart-p-35.html

Either will work on aluminum/steel and I'm assuming your not worried about a polished surface as you are sandblasting. There is another prep for that.

[Redneck]

Straight to paint. Baking speeds the cure but unless you are talking about high temp engine paints and the like, that's all it does when it comes to common rattle can paints.

Just to empahsise my noobness.... by straight to paint you mean sandblast, prime, then paint.... not sandblast then paint....I know I sound like dodo boy but I don't want to misunderstand anything.

Just saw posplayr's post. I do want a good finish on some of the pieces, so if it is a hidden piece just paint on the sand blast if it is something that visible and I want it to look pretty prime and sand, prime and sand or do I need to clean up the roughness of the sandblasting.... I am sandblasting to remove rust in concave areas and places that are hard to hand sand or power too sand.

[SqDancerLynn1]

Sand blasting leaves less than desirable finish. 4-6 coats of sand able primer, light sand between coats, 1 final coat of non sand primer and paint

[Redneck]

Sand blasting leaves less than desirable finish. 4-6 coats of sand able primer, light sand between coats, 1 final coat of non sand primer and paint

That might explain the blotchiness...i did not use a nonsandable primer prior to putting on my ground coat and paint. Yay...thanks a lot.

Paul

[Nessism]

Just to empahsise my noobness.... by straight to paint you mean sandblast, prime, then paint.... not sandblast then paint....I know I sound like dodo boy but I don't want to misunderstand anything.

Just saw posplayr's post. I do want a good finish on some of the pieces, so if it is a hidden piece just paint on the sand blast if it is something that visible and I want it to look pretty prime and sand, prime and sand or do I need to clean up the roughness of the sandblasting.... I am sandblasting to remove rust in concave areas and places that are hard to hand sand or power too sand.

Sandblast...prime...top coat

Prime can mean various things and various materials. Since you are using rattle cans that narrows things greatly; just get what they recommend - typically only one primer.

Top coat can mean various things too but again, just use what is recommended within the mfgers recommendations.

If you make the move to automotive type paint there are all kinds of extra materials and steps that can be added to improve the finish.

[Darkstang]

Sandblasting... if you blast any kinda sheet metal such as the tank, use LOW PRESSURE! You can actually warp sheetmetal with a blaster.

If you want to rattle can, Clean the parts after blasting with a good degreaser that leaves no trace. Acetone can be had at Lowes or Home Depot pretty cheap.

Sandblast will leave a matte surface, depending on media used to blast. To smooth this out, if you want, they make High Build primer in rattle cans now. This will have a hiding effect for light scratches and matte surfaces and allows you to sand to a smooth finish. Then paint with rattle can and you can even get rattle can clear top coat as well.
Ken

[koolaid_kid]

Straight to paint. Baking speeds the cure but unless you are talking about high temp engine paints and the like, that's all it does when it comes to common rattle can paints.

Request for clarification. If you use high temp engine paints, what does baking do?

[Nessism]

Request for clarification. If you use high temp engine paints, what does baking do?

It depends on the paint but many high temp paints don't reach full strength/chemical resistance until they are baked (says so on the can). I assume the temperature causes some chemical reaction to take place.

[Hammered]

Whether you sand after sandblasting depends on the finish youre after. Ive blasted several parts of my 750 that Im building. For a matte finish, Ive left it. For a more polished finish I sand after blasting and before priming. No matter which way you go, always clean the part. I use an air nozzle to remove the main debris and wipe everything down with a prep cloth. If its a part thats been sitting but already prepped, I wipe it off with a dry, clean micro fiber rag.