What Aluminum

[popskull]

What aluminum would be good for making coolant reservoirs? Right now I am using 6061-T6, but its tough to bend and I am looking at revising the way I make the tanks so that most of the seams will be bent rather than welded. I currently use 1/8" because it's readily available and pretty easy to weld with no warping.

I know the alloys with more copper are easier to bend, but also more prone to corrosion. I polish many of these tanks, so I need it to withstand some weather and keep some corrosion resistance.

Any recommendations?

Right now I am thinking of sticking with 6061, but cutting a relief line along the where the bend will be. Not sure if this would make the aluminum porous though. Reason I am looking to change is so that I can drop a few off at the CNC machine and have them cut out. Should save cost and time on cutting with an angle grinder...

 

[SM Racing]

I would use a 5000 or 3000 aluminum. Its easier to form and welds easily. Probably go with .040-.062 at the thickest. No need for the extra weight and mass. Might even go as thin as .023 depending on design.

 

[dieselgarage]

We build a coolant surge tanks that the sheet material is 5052 an the machined parts are 6061T6511. These are going in HD trucks. It's not our design so we just build to print but somewhere and engineer had reason to pick these materials. But then again, I guess he could have just guessed.

 

[gorilla]

5052 is a good choice for forming and welding it also machines well. Be advised that 6061-T6 is not a good choice for welded joints. It loses it's T-6 condition and will often crack along the weld if it's under stress. I learned this on some formula 5000 wings years ago.

 

[popskull]

Thanks for the advice guys, the 6061 is not being used under stress, so I should be good. I just knew it would polish up real nice and I am familiar with welding it. I will have to see what the price difference is between the 6061 and 5052. I am willing to bet its probably a fair amount cheaper.

Gonna have to look into the thickness a bit more too.

 

[Jagmandave]

What about annealing it before you try to bend it?

 

[V-10 Killer]

I was googling something like this yesterday. Sounds like quite a few fabricators that make aluminum fuel tanks and resevoirs like 0.90ish 3003 aluminum

 

[popskull]

What about annealing it before you try to bend it?

Not entirely sure I know what you mean... does that consist of heating it? The best heat source I have at the moment is a MAPP gas torch, which I tried on my last reservoir lid, but it didn't get the 1/8" material hot enough, which would be another indication that I should probably move to thinner material.

 

[NASTYZEN]

I use 3003 for my tanks and reservoirs. Forms easy and wont crack from vibrations or scratches. Will buff out just like 6061T-6.

 

[Jagmandave]

Not entirely sure I know what you mean... does that consist of heating it? The best heat source I have at the moment is a MAPP gas torch, which I tried on my last reservoir lid, but it didn't get the 1/8" material hot enough, which would be another indication that I should probably move to thinner material.

here's a YT vid on how he does it with a hand torch, I use oxy acet myself, but you don't have to get it red hot or anything.

Here's another way, just fyi, from a home shop fabricator

"the method I use for this is to draw a line across the back side of the bend with a Sharpie marker. Heat along that line with a regular old propane torch until the line disappears. Go bend."

aluminum does not like sharp corners tho, so bend it over something with a radius.

 

[TheIceMan]

I use 3003 for my tanks and reservoirs. Forms easy and wont crack from vibrations or scratches. Will buff out just like 6061T-6.

Ditto! .063 or .080 thickness works great.

 

[retrobuilder]

5052 yes- forms well and easy to cut. Used alot on enclosures and brackets form marine and other applications. Welds well and takes paint fine.

 

[bullnerd]

3003 here too,for any forming/bending parts and 5052 for more flat/some bends.

Can get from McMaster carr in a pinch too.

Dont think bending 6061 is highly recomended,and only perpendicular to the "grain" if you have to.

 

[popskull]

3003 might be it then! Looking at probably 0.080" thick though, since I am relatively new at welding, I don't know if I trust myself enough to weld much thinner just yet.

What filler rod do you use on it? I have 4043 right now, should I chance to 5356?

 

[bobadame]

Use the 4043 rod. It works well. It's more ductile than the 5356.

 

[popskull]

Awesome! Thank you!