I'm going to be fabricating some small aluminum bits out of some .05" sheet stock. I have no idea what kind of aluminum it is.
I want to polish (not to a super high luster, but bright) and clear coat the pieces. Any tips on procedures and products would be most welcome. I don't have a buffer or an HVLP gun so all work will be done by hand. Finishes will have to be of the spray can, brush on or dipped variety. Luckily the parts are small and there are only a few of them.
Thanks.
sac
You'll need more elbow grease than you can even imagine without a buffer wheel, so good luck
I've hand polished a TON of aluminum parts for my bike. Super easy. After final cutting/filing just sand the heck out of it with maybe 600 grit. Mayeb work your way from 300 - 600 - 1200. I've even used steel wool. Just need to get the scratches out. Then finish up with a couple elbow grease applications of metal polish. I have been using Wenol and like it a lot. The rag will turn black as the part turns shiney. Buff it out with a cotton rag. No clear coat necessary. just clean/re-buff when/if necessary with more metal polish down the road. I think clear coat paint would be more trouble than it's worth because if it chips/cracks/turns yellow you can't simply clean it up like you can with a raw aluminum part. Maybe if you're in a very corrosive environment this would be different, but in that case i would consider powder coat instead.
Quote from: Dietrich on November 18, 2010, 02:34:05 PM
I've hand polished a TON of aluminum parts for my bike. Super easy. After final cutting/filing just sand the heck out of it with maybe 600 grit. Mayeb work your way from 300 - 600 - 1200. I've even used steel wool. Just need to get the scratches out. Then finish up with a couple elbow grease applications of metal polish. I have been using Wenol and like it a lot. The rag will turn black as the part turns shiney. Buff it out with a cotton rag. No clear coat necessary. just clean/re-buff when/if necessary with more metal polish down the road. I think clear coat paint would be more trouble than it's worth because if it chips/cracks/turns yellow you can't simply clean it up like you can with a raw aluminum part. Maybe if you're in a very corrosive environment this would be different, but in that case i would consider powder coat instead.
I'm four blocks from the Pacific, summers are very foggy and the bike will not be garaged, cover only. :-\
I may just resign myself to perpetual polishing.
sac
I realize you live in the PRoK, but what are the chances you could get a hold of a home anodizing kit?
Quote from: Buckethead on November 18, 2010, 05:20:14 PM
I realize you live in the PRoK, but what are the chances you could get a hold of a home anodizing kit?
FedEx will ship anything. Drugs, small arms, undocumented workers. I don't think chemicals will be a problem. Order in AZ ship to CA as a stack of books. Simple.
I didn't know those existed. Will they give a semi-bright silvery finish?
sac
Working with aluminum in the ocean, it will eventually start pitting if left untreated. We always continually do fresh water washdowns. Just different grits of paper will work for shine. As far as any clear coat for this...?
valspar rattle can lacquer from lowe's. I put polished perforated steel in my belt covers and used that stuff to seal it. I've also used it to seal polished steal on small sculptures. 2-3 thin coats after an alcohol bath
Quote from: cbartlett419 on November 29, 2010, 06:41:10 PM
valspar rattle can lacquer from lowe's. I put polished perforated steel in my belt covers and used that stuff to seal it. I've also used it to seal polished steal on small sculptures. 2-3 thin coats after an alcohol bath
Steel and aluminum are two very different metals.
I've used Eastwood's "Diamond Clear" with good results on both bare steel and aluminum.
http://www.eastwood.com/ew-diamond-clear-gloss-bare-metal-aero-11-oz.html (http://www.eastwood.com/ew-diamond-clear-gloss-bare-metal-aero-11-oz.html)
The progression I use is:
- 600 grit
- 1200 grit
- Medium Scotchbrite
- Fine Scotchbrite
- Fine Steel Wool
- Wenol or Semi-Chrome Polish
IMO, the Diamond Brite looks better/lasts longer if you leave off the polish. If you polish, and do it right, you'll have a finish that is as shiny as chrome. Without the polish you end up with a nice "semi glosss" look.
And if you have more than one or two tiny items to do, I'd suggest, at minumum, investing in a Dremel tool or some such. If I don't use one, I end up getting rushed and leaving marks from one level that can't be removed by the next. (i.e. marks made by the 1200 grit that would take forever to remove with the Scotchbrite.)
For bigger pieces, a Roll-lok attachment for a drill and some fine Scotchbrite discs make for a really nice brushed surface.
http://www.mechanicstoolsupply.com/Abrasives/Roloc%28TM%29-Surface-Conditioning-Discs/index.html (http://www.mechanicstoolsupply.com/Abrasives/Roloc%28TM%29-Surface-Conditioning-Discs/index.html)
I'd go about the same route ^^^^^
Surface finishes are all about patience and prep so don't get antsy when it starts to take too long. Do each level deliberately, and when you move to the next finer level of abrasive you still have scratches from the last batch, go back over it.
Shit, I just re-read your post dlearl. Anyone who has any sort of shop/garage and fabrication ability should own a Dremel. Christmas is coming up..... :) I use mine all the time and polishing wheels are a dime a dozen wherever they sell Dremel stuff. Just don't get one of the cordless ones. Here's the mirror polish I did on my bike a few years back. You don't have to go this high gloss, I just did it to prove to myself I could do it.
(http://i6.photobucket.com/albums/y239/Jervisaurus/fullframe.jpg)