Aluminum bending after anodize
Aluminum bending after anodize
(OP)
I have items made for me in Eastern Europe. One of my items uses an aluminum faceplate (about 1x2 inches) that is .5mm to .6 mm thick and 1050 alloy. The faceplate must be printed before final manufacturing. The printer wants to anodize the surface first before silk screening. After printing, the faceplate much be bent 90 degrees to form a right angle on one end.
Since anodize does form a ceramic coating will it cause the base metal to fracture or crack during the bending? If it cracks, is this only a local surface cosmetic issue, or is the metal compromised in strength? Printing after bending is not an option and the printer refuses so use any alloy other than 1050. I have been doing the bend operation for many years with no problems, but now the printing process is changing and the anodize step added.
Am I headed toward problems or can I get away with this?
BTW, the products are sold world wide into the model airplane hobby market.
Thanks for some expert advise. I have no clue.
Since anodize does form a ceramic coating will it cause the base metal to fracture or crack during the bending? If it cracks, is this only a local surface cosmetic issue, or is the metal compromised in strength? Printing after bending is not an option and the printer refuses so use any alloy other than 1050. I have been doing the bend operation for many years with no problems, but now the printing process is changing and the anodize step added.
Am I headed toward problems or can I get away with this?
BTW, the products are sold world wide into the model airplane hobby market.
Thanks for some expert advise. I have no clue.





RE: Aluminum bending after anodize
do all process forming, machining prior to anodize & chem film.
yes asking for problems.
alternative would be to chem film only instead of anodize.
I have silk screened parts mark after chem film.
RE: Aluminum bending after anodize
RE: Aluminum bending after anodize
so cracking the parent material is possible.
depending on what type of anodize, "hard or sulfuric or chromic". the pentration & build up will be more from
hard anodize(.0016-.0024")
may be anodize printing might be an option.
RE: Aluminum bending after anodize
You may be better off going chem film only if your printer will do that, if not just go ahead and bend the part,any resultant corrosion will be along the bend line only.
B.E.
RE: Aluminum bending after anodize
B.E.
RE: Aluminum bending after anodize
RE: Aluminum bending after anodize
thanks for the constructive advice
my information originally came from Booklet from
Barry Avenue Plating many years ago.
booklet states 50% penetration 50% buildup.
I based this to be true because over the year of inspecting
fabricated aluminim sheet metal & machine parts before & after Anodize.
My apologies if I misconstude the physical nature.
however the statement is true about the penetration & buildup. from the physical change.
It's been a while since I have looked at some micro graphs
of the physical penetration of the Anodize.
But even thou it's not good practice to bend Anodize sheet metal & yes it could crack.
RE: Aluminum bending after anodize
The finish product is stored indoors and only sees water when the model is lost and if it rains then.
Cost is a major issue, and I do not have the luxury of exotic finishing work or printing after bending. I must print a sheet and then cut out the individual pieces prior to the mentioned bend. In the past I have made a sharp bend and never had a problem, but this was with non anodized parts. The anodize is there for only one reason - to let the ink from silk screen penetrate the surface and adhere. It is not there for environmental reasons.
So, is the consensus that I can do this?
RE: Aluminum bending after anodize
then visualize the parts. ultimately you need to decide.
good luck
RE: Aluminum bending after anodize
RE: Aluminum bending after anodize
Inspector,shearing, bending, planishing, welding & so on
then as a apprentice machinist for a gear company
while I was going to college.
then assemble small projects like the shuttle, dc-10
atlas missle tanks
If any my guys ever asked me to bend anodize sheet metal
I would say no!!!
it's not standard manufacturing practice period.
but there is always a variance to the rule and that what make the world go round..
however being this is a model airplane and asthetics is not important ya give it a try.
RE: Aluminum bending after anodize
I can also use 6082 alloy and not anodize at all, but the printing process is more costly and does not yield as good a visual appearance nor as durable. The print shop will not use 6082, or that would be my choice.
Or I can leave all printing off, but then my products look poor.
Thanks guys.
RE: Aluminum bending after anodize
In some sections of the sheet metal industry it is common practice to buy pre-anodised sheet aluminum in the softer grades and fabricate parts by shearing and bending. As previously stated the only detrimental effects will be some loss of corrosion resistance on the bend line.
You may also be able to buy your sheet pre anodised saving you another step 1050 is a pretty soft alloy as long as do not go over a strain hardening of H12.
As far as bending pre anodised material is concerned, you will see some cloudiness at the bend line but that is all.
I would suggest that you do a trial run.
B.E.
RE: Aluminum bending after anodize
You say the anodizing is only to allow the ink to adhere and not for corrosion protection at all. So use a different ink..plain and simple and skip the anodizing all together. Sounds like your printer is not that skilled or knowledgable about screen printing. There are plenty of screen inks that will adhere properly to aluminum without anodizing. We use Nazdar screen inks all the time and the 8900 or ADE series (better but its a 2 part mix which can be a slight hassle) will all work without issue if properly applied/dried.
RE: Aluminum bending after anodize
The hitch to Nazdar 8900 may be the necessary precoat needed. What do you use? Because it is solvent based, is a new screen needed each time or can the screen be cleaned of the 8900 after a run?
RE: Aluminum bending after anodize
Now it is looking like 1050 may be too soft. I know I said it was non structural, but the bend part does have a small spring sitting on it, and the spring seems to be taking the bend out. Trying to work with two suppliers 4000 miles away when English is a second language is a real hassle. It looks like we need to find a new silk screen house that is not locked into anodized 1050.
RE: Aluminum bending after anodize
RE: Aluminum bending after anodize
Do you put this on over bare aluminum? Do you use any coating over it? Is the ink resistant to normal solvents after drying? I like to use an ultrasonic tank with detergent to clean my products after heavy use in the field. I also use Gunk Engine aerosol spray cleaner to remove deposits of oil and sometimes aerosol brake cleaner. Anything ring a bell as being a no no?
RE: Aluminum bending after anodize
Most commercial 1050 is supplied with a hardness of H14 or 1/4 hard, you can buy harder up to H18 depending on what your supplier has. If your spring is deflecting your part you may want to go up a notch on the hardness.
Are you supplying these parts to your printer or are they being made in eastern Europe,and then shipped back to you?
At the risk of prying, is this a cut off timer for a competition model?
B.E.
RE: Aluminum bending after anodize
I ship critical gearworks to the assembly house in e europe. They produce to my specs. The issue of printing and faceplates never came up until they lost their long time supplier. Volumes are not high enough to be able to wield a big stick on a print house. The one currently being talked to demands they supply their own sheet metal which is 1050. Tests over there yesterday shows it to too soft. In the past the assembly house supplied 6084 sheet to the printer. But,it was a obsolete print process I now find out and no one still uses it.
Yes, among other functions, engine cutoff is performed. That is one of the simpler products made. But the bend is directly associated with the cutoff function.
RE: Aluminum bending after anodize
There is a big difference between the mechanical properties of 1000 series aluminum and 6000 series.
It sounds to me that you would be better off keeping your original material and finding a different printer.
Your device sounds similar to the timers I used in competition 40 years ago, fuel cut off after 30 seconds de- thermalise after 3 minutes.
B.E.
RE: Aluminum bending after anodize
Yep, you got it. You were using a Tatone, most likely. Maybe a KSB. Both long gone from the market. And, our motor runs now are more like 9 or 7 seconds. With the engine turning 30,000 RPM, in 30 seconds, it would be a tiny dot in the sky in 30 seconds. And the DT is now usually 2 minutes unless you fly in the California desert.
Changing printers is not quite as easy in e europe as it is in the US. Fewer choices.