Jump to content

Sandblasting an Aluminium Frame?


Jigghead

Recommended Posts

I have an alu frame that I'm running out of patience with trying to get all the paint off. Is sandblasting before shining/buffing the frame a viable option?

Link to comment
Share on other sites

Probably ok to sandblast if you are going to paint it, but not if you want a nice shiny raw aluminium finish. Some have been having great results with Plascon Remove All paint stripper. Apparently applying it, waiting a while and then hosing off layers of paint.

Link to comment
Share on other sites

Probably ok to sandblast if you are going to paint it, but not if you want a nice shiny raw aluminium finish. Some have been having great results with Plascon Remove All paint stripper. Apparently applying it, waiting a while and then hosing off layers of paint.

 

Ja, it'll be raw and polished once complete, so more paint stripper it is then...

Link to comment
Share on other sites

i have sandblasted several frames but i think you should be careful as to what your intended use of the frame will be, me i built single speed hardtail mountain bikes so wasnt really concerned about stressing the material and making the frame weaker. i dont see why taking the paint off with sand would weaken the frame but would be slightly nervous doing it to a jump bike for example.

dont know if thats really a possibility but have heard talk around that kind of thing so was a little nervous at first but not not so much.

the last frame i did i asked the guys to media blast rather than sand( apparently they use little plastic beads instead of sand)

both worked just as well as far as i can tell but the media blast left a slightly smoother finish in the end which may or may not be beneficial. dont get me wrong i think only steevie wonder could really tell the difference but that was my perception anyway.

i have a guy that i use if you want contact details let me know ill send on to you. they can also powder coat etc so a nice one stop shop for what i was trying to achieve.

Link to comment
Share on other sites

If you want to polish your frame rather not use the sandblasting option. Sand blasting leaves small pit marks in the frame surface which you need to polish out later. Use paint stripper and some elbow grease my friend. Only way :thumbup:

Edited by Wolfie1
Link to comment
Share on other sites

I spent a whole day with paint stripper to get every little piece off. It's worth it in the end. Just have to keep reminding yourself of that.

Link to comment
Share on other sites

just watch out for sandblasting. Had a frame done and the sand was too course. Frame is now in the bin.

Alu is soft. I now use paint stripper.

Link to comment
Share on other sites

Guest Smimby

Do a search here someone mentioned a VERY good paint stripper.....that ticks all the boxes

Link to comment
Share on other sites

Plascon RemovALL

 

NB -- USE AS PER INSTRUCTION and do not get impatient.

 

Ovencleaner can also work wonders on some paints.

 

Avoid any blasting - you will not shine it up again.

Edited by porqui
Link to comment
Share on other sites

Thanks fellas for the feedback.

 

i have sandblasted several frames but i think you should be careful as to what your intended use of the frame will be, me i built single speed hardtail mountain bikes so wasnt really concerned about stressing the material and making the frame weaker. i dont see why taking the paint off with sand would weaken the frame but would be slightly nervous doing it to a jump bike for example.

dont know if thats really a possibility but have heard talk around that kind of thing so was a little nervous at first but not not so much.

the last frame i did i asked the guys to media blast rather than sand( apparently they use little plastic beads instead of sand)

both worked just as well as far as i can tell but the media blast left a slightly smoother finish in the end which may or may not be beneficial. dont get me wrong i think only steevie wonder could really tell the difference but that was my perception anyway.

i have a guy that i use if you want contact details let me know ill send on to you. they can also powder coat etc so a nice one stop shop for what i was trying to achieve.

 

I've thought about powder coating but have heard that often the heat involved will compromise the welds, any thoughts on this?

 

If you want to polish your frame rather not use the sandblasting option. Sand blasting leaves small pit marks in the frame surface which you need to polish out later. Use paint stripper and some elbow grease my friend. Only way :thumbup:

 

I was afraid that this would end up being my only option, I was just hoping tho...

Link to comment
Share on other sites

I stripped a frame with Plascon Remove All. Read the instructions and follow them. I applied it as per the label (put it on thick) and left it for 24hrs. Most of the paint was removed with an old bank card first and then a high pressure cleaner set on its lowest setting. The paint just peeled off. I had to redo a few stubborn patches but we are talking about small patches in awkward corners. Very small.

 

Either that or find someone that can chemically strip it. THAT is the easiest way. I did one frame chemically. Cost me R100...!

Link to comment
Share on other sites

Your biggest problem with sandblasting is not the rough surface problem as mentioned. Modern aluminium frames, especially super lightweight frames like basically all of them above R10k, are shot peened or laser peened. This is like sand blasting but with special beads, probably glass, that finely peens the metal giving it some surface tension and thus crack resistance. Peening is done in addition to heat treatment because the metal is drawn so thin that it needs every bit of help it can get. The beads they use are small, 0.3mm in dia or so. Peening would leave the surface looking like some of that fake antique silver or pewter ware, if you were to look at it under a low power microscope. By sandblasting the aluminium, you remove the peening and weaken the frame. Peening is one of the reasons frame manufacturers will void the guarantee if you were to repaint it. It isn't the paint job that does the damage but the surface preparation over which they have no control. I suggest you use paint remover and very little sanding. That said, if it is an el-cheapo frame with welds that look like chicken poop and toothpaste, blast away.

Edited by Johan Bornman
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Settings My Forum Content My Followed Content Forum Settings Ad Messages My Ads My Favourites My Saved Alerts My Pay Deals Help Logout