SpreadEagle
11-22-2006, 11:23 PM
Many of you have already been down the DIY road and have made your own devices using aluminum. Some items seem to be left in the "raw/sanded/polished" state, some have been painted, and some have been more elaborately coated - powder coating. I am an ex Lochheed Martin engineer and have much experience with treating aluminum and paint systems used for aerospace manufacturing. You too, the DIY'er, can have aerospace class aluminum parts that will paint up well, and resist corrosion.
When working with aluminum blocks, rods, plate, you will want to decide upon a finish. Some folks like some things to remain silver, and other like things to be "camera black" like most lenses and attachments.
Consider making a rail system for a camera rig. If you buy 1" by 2" aluminum block, drill two holes through it for rods, tap some screw holes, break the sharp edges and in general clean it up with light sanding, you will then arrive at an important decision point.
If you have the funds to have the parts anodized or powder coated, that yields the most professional look, and great corrosion protection. But if you can not afford to have that done but still want that pro look, there are some very simple steps you can take to put a chemical conversion coating on the aluminum.
This coating is done by imersing or brushing a solution onto the bare cleaned part. The coating does several things. First and foremost, it provides corrosion resistance. Handling with sweaty hands being in close proximity to salt spray or salt air will cause untreated aluminum to begin to oxidize or corrode. If the aluminum is left bare, then you will notice that a black residue will begin coming off the part onto your hands, your nice white shirt, and such. You can really see the black residue on the aluminum, but it will continue to come off on you.
The other reason you might want to treat the aluminum is to provide a much better surface for primer/paint adhesion. If you paint a bare aluminum part, you will begin to note that the paint comes off pretty easily. Unless you buy paint designed for coating aluminum, you will not have a durable finish.
Purchasing a bottle of Alodine 1200 costs about $17. This quart-size will treat about 100 square feet of surface. In addition to the Alodine solution, you should buy a chemical cleaning solution, such as Alumiprep #33 or Metal Prep #79. I prefer the latter. Each of these sell for about $17 per quart.
You can find all of these at the following URL's:
http://www.aircraftspruce.com/catalog/cspages/alodine1201.php (http://www.aircraftspruce.com/catalog/cspages/alodine1201.php)
http://www.aircraftspruce.com/catal...s/alumiprep.php (http://www.aircraftspruce.com/catalog/cspages/alumiprep.php)
http://www.aircraftspruce.com/catal...s/metalprep.php (http://www.aircraftspruce.com/catalog/cspages/metalprep.php)
These folks are based out of southern California, USA. Outside of US, you might want to search for websites/suppliers that cater to the light aircraft DIY'ers. They usually sell small quantities to the retail purchaser, rather than to industrial customers.
Once you have your finished aluminum parts cleaned, and have applied the chemical conversion coating, you can then prime and paint using most good paint products. I myself prefer epoxy type paints for a very hard and durable surface coating. Zinc Chromate primers (or newer replacements for Zinc Chromate) provide the next level or protection to the chemically converted aluminum.
If you do bypass all this, try using an ETCHING primer. This chemically etches the surface of the aluminum, and then the primer dries/bonds to that surface. One I have used is called TEMPO and can be found at this URL:
http://www.aircraftspruce.com/catal...fetchprimer.php (http://www.aircraftspruce.com/catalog/cspages/temposelfetchprimer.php)
Check your local Home Depot or Loews or other home improvement/hardware stores for similar primers.
Hope this might help some of you produce truly professional DIY parts!
:beer:
When working with aluminum blocks, rods, plate, you will want to decide upon a finish. Some folks like some things to remain silver, and other like things to be "camera black" like most lenses and attachments.
Consider making a rail system for a camera rig. If you buy 1" by 2" aluminum block, drill two holes through it for rods, tap some screw holes, break the sharp edges and in general clean it up with light sanding, you will then arrive at an important decision point.
If you have the funds to have the parts anodized or powder coated, that yields the most professional look, and great corrosion protection. But if you can not afford to have that done but still want that pro look, there are some very simple steps you can take to put a chemical conversion coating on the aluminum.
This coating is done by imersing or brushing a solution onto the bare cleaned part. The coating does several things. First and foremost, it provides corrosion resistance. Handling with sweaty hands being in close proximity to salt spray or salt air will cause untreated aluminum to begin to oxidize or corrode. If the aluminum is left bare, then you will notice that a black residue will begin coming off the part onto your hands, your nice white shirt, and such. You can really see the black residue on the aluminum, but it will continue to come off on you.
The other reason you might want to treat the aluminum is to provide a much better surface for primer/paint adhesion. If you paint a bare aluminum part, you will begin to note that the paint comes off pretty easily. Unless you buy paint designed for coating aluminum, you will not have a durable finish.
Purchasing a bottle of Alodine 1200 costs about $17. This quart-size will treat about 100 square feet of surface. In addition to the Alodine solution, you should buy a chemical cleaning solution, such as Alumiprep #33 or Metal Prep #79. I prefer the latter. Each of these sell for about $17 per quart.
You can find all of these at the following URL's:
http://www.aircraftspruce.com/catalog/cspages/alodine1201.php (http://www.aircraftspruce.com/catalog/cspages/alodine1201.php)
http://www.aircraftspruce.com/catal...s/alumiprep.php (http://www.aircraftspruce.com/catalog/cspages/alumiprep.php)
http://www.aircraftspruce.com/catal...s/metalprep.php (http://www.aircraftspruce.com/catalog/cspages/metalprep.php)
These folks are based out of southern California, USA. Outside of US, you might want to search for websites/suppliers that cater to the light aircraft DIY'ers. They usually sell small quantities to the retail purchaser, rather than to industrial customers.
Once you have your finished aluminum parts cleaned, and have applied the chemical conversion coating, you can then prime and paint using most good paint products. I myself prefer epoxy type paints for a very hard and durable surface coating. Zinc Chromate primers (or newer replacements for Zinc Chromate) provide the next level or protection to the chemically converted aluminum.
If you do bypass all this, try using an ETCHING primer. This chemically etches the surface of the aluminum, and then the primer dries/bonds to that surface. One I have used is called TEMPO and can be found at this URL:
http://www.aircraftspruce.com/catal...fetchprimer.php (http://www.aircraftspruce.com/catalog/cspages/temposelfetchprimer.php)
Check your local Home Depot or Loews or other home improvement/hardware stores for similar primers.
Hope this might help some of you produce truly professional DIY parts!
:beer: