Aluminum questions......

[David Grason]

I picked up the aluminum the other day. Yesterday, I glued up the 2 sides of my teardrop but when it came time to trim it to shape, I quickly found that this is some darn gnarly stuff to work with.

I tried to cut the excess aluminum off with a set of air powered metal shears. I don't know if this tool is not working right or I just didn't have the hang of it but man, it can tear up a project faster than anything. However, it did not give me the results I was looking for and I tried a half dozen different techniques. No, I think I'll get my money back on THAT tool.

Next I tried my laminate trimmer. It worked very well up until the bearing sheared off. Now I gotta say that I built laminated furniture and counter tops for a number of years and I've never had a bearing do that. Of course as soon as the bearing was gone, the router would jump out of the line I was trying to maintain and cut whatever the hell it wanted to. Fortunately I believe that I can cover the ooboo with molding.

So I put my spare laminate bit in there and this time I only got about 6 inches done and the thing started jumping around like a popo stick. It appears as though I've melted the aluminum and it piled up behind the cutting surfaces rendering them totally useless and ruining a brand new $30 bit.

I'd love to post pictures so you could see what I'm up against and maybe offer suggestions but I can't even get the pics to post right. I think I need a vacation just from building my teardrop.

So if anyone has any idea what the correct and easy/normal way to trim this aluminum is, please help me out. This drove me crazy and I can't do it anymore in the future. There's got to be a better way.

[SteveH]

David,

I too had a lot of problems trimming the aluminum (.050" 5052) on my tear. I cut the sheets to length with a saber saw, not really a problem, before glueing them to the sides because all I could buy here was 12 foot lengths in 5 foot wide.

However, as you have experienced, trimming the aluminum to the profile was a bear. I used a new laminate bit in a router and the going was slow. I had to stop frequently (about every two foot or so) and clean the aluminum off the bit before I could continue. I found the slower I went, the better it was. It was not a pleasant experience, but eventually I got it done using that method. Good luck with yours.

[Denny Unfried]

Hi David,

Even my routers with speed control can't turn slow enough to keep from melting aluminum. I plugged my smallest router into a Variac (voltage control) and cut the voltage to 40v. The 1/2" flush cutting carbide bit went through it like butter and I went into detail at my web site. Same thing with the 1/4" bit that was used to cut the windows. I have seen router speed controls in Harbor Freight catalogs for something like $12.

We've all ran into these little problems and thanks to Mike's Forum it's easy to find answers to almost anything.

Denny

[David Grason]

Thanx Steve. Yes, I could trim the aluminum to a rough shape using the metal shears. They do ok when there is good clearance on either side of the jaws. But when I run up against plywood on one side or the other, they quickly bind up. Usually ends up kinking the aluminum and fortunately, I should be able to cover those with moldings as I said before. (whewwwwww)

I think where I ran into problems with the laminate trimmer is when I tried to use the router in place of the shear. If I was cutting through virgin aluminum, the laminate bit was cutting on 180 degrees of it's circumfrance. On the other hand, if I can trim it in really close with something else, the laminate bit can pretty easily do the last shape up because it's only cutting on a very small fraction of its circumfrance. I think that's what I'm going to try next. I'll keep everyone aprised.

Still have no idea how to post pictures though.

Denny, I posted this reponse and then I saw where you had posted right ahead of me. Thank you. I didn't even think about turning the speed down. DOH!! My laminate trimmer is a Ridgid and it's got a speed control on it. Man, why didn't I think of that?

Also I got better results with my first bit. It's a flush cutter whereas my back-up bit cuts on a bevel. Do you reckon that has anything to do with it?

One other thing I will try as well. Half my tools are electric and the other half are air powered. I've got a HUGE compressor so it's a rare tool that it can't keep up with. I think when I use the Ridgid Laminate trimmer next time, I'll keep a blow nozzle on the end of the air hose and keep blowing the aluminum shavings away. It just occured to me that shards of aluminum could have gotten in there and messed things up without me even seeing them.

[Denny Unfried]

Thanx Steve. Yes, I could trim the aluminum to a rough shape using the metal shears. They do ok when there is good clearance on either side of the jaws. But when I run up against plywood on one side or the other, they quickly bind up. Usually ends up kinking the aluminum and fortunately, I should be able to cover those with moldings as I said before. (whewwwwww)

I think where I ran into problems with the laminate trimmer is when I tried to use the router in place of the shear. If I was cutting through virgin aluminum, the laminate bit was cutting on 180 degrees of it's circumfrance. On the other hand, if I can trim it in really close with something else, the laminate bit can pretty easily do the last shape up because it's only cutting on a very small fraction of its circumfrance. I think that's what I'm going to try next. I'll keep everyone aprised.

Still have no idea how to post pictures though.

Denny, I posted this reponse and then I saw where you had posted right ahead of me. Thank you. I didn't even think about turning the speed down. DOH!! My laminate trimmer is a Ridgid and it's got a speed control on it. Man, why didn't I think of that?

Also I got better results with my first bit. It's a flush cutter whereas my back-up bit cuts on a bevel. Do you reckon that has anything to do with it?

Should be no problem with the straight bits. I used the same 1/4" and 1/2" flush cutting bits to cut aluminum that was used to cut the profile on the 3/4" birch but just slowed it way down. You shouldn't need any air and the chips will fly out on their own it they aren't melted onto the cutter. One word of caution is you will want to protect the aluminum because the chips will get between it and the router and scratch it up badly. I used the same piece of Masonite that was used for a profile to protect it.

Denny

[dguff]

When I cut my side profiles I cut the aluminum at the same time. I made a sandwich of the two pieces of plywood with two aluminumsheets in the middle. I screwed them together where the material was going to be removed and also clamped all around the edges. It was very stable. I then traced my outline and cut the whole thing at one time with a jig saw. My two sides end up identical and the aluminum is already trimmed to the exact size of the plywood. Worked for me!

Jerome

[David Grason]

One word of caution is you will want to protect the aluminum because the chips will get between it and the router and scratch it up badly.

Actually, the aluminum was already scratched pretty badly even when I picked it from the metal supply company. I said something about it at the time and they agreed to let me pick through the stack but even separating the pieces was scratching them somewhat. So I made the decision then and there to just live with the scratches until further into the build when I would get an opportunity to buff the aluminum. I figure when Jesse James can hammer these gorgeous gas tanks for his choppers out of this stuff, and do it all by hand, I should have no problems getting this to look good when I'm done. Also, I can't see that I'm going to be able to work around this in my garage and not scratch it further anyway. Something will fall on it or I'll move it while watching one side and the other will bump into my big tool box or something ......... I'll just buff it when I'm done.

[Kevin A]

On the other hand, if I can trim it in really close with something else, the laminate bit can pretty easily do the last shape up because it's only cutting on a very small fraction of its circumfrance. I think that's what I'm going to try next. I'll keep everyone aprised.

David, you might look into something like an air nibbler. I see Harbor Freight has one on sale http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=46061 It will cut up to 16 gauge sheet metal and should work for trimming your aluminum close enough to allow you to finish with the laminate trimmer.

[Denzagrad]

I used a jig saw with a metal blade carefully following the plywood edge, erring on too much overhang versus cutting into the wood. Afterwards, I filed the excess down to the wood. I only had to do this with the sides. The roof was exactly 4ft wide and I had four foot wide aluminum. Those edges lined up without a problem. For the roof length I used the jig saw to cut it to length. To prevent damage to the paint, I taped about 2 inches of thick tape on both sides the line being cut. The trim covered up the joints.

[Keith]

For straight cuts the cleanest and easiest way we have found is to put a metal fence up and cut the alumunim with a skill saw. The wood blade makes a nice clean cut and leaves a nice edge on the aluminum. It also is easy to get a straight edge.

When cutting aluminum with a saber saw it works best to keep the blade coated with WD40. It helps keep the aluminum from building up in the blade. The cuts seem to go much easier. I have also found that when cutting aluminum in the band saw the WD40 also speed up the process. I think it helps keep the heat down so the metal doesn't melt.

You might try having someone spray WD40 on your router bit to help with the heat problem.

Keith.

[johnp]

. It appears as though I've melted the aluminum and it piled up behind the cutting surfaces rendering them totally useless and ruining a brand new $30 bit.

I'd love to post pictures so you could see what I'm up against and maybe offer suggestions but I can't even get the pics to post right. I think I need a vacation just from building my teardrop.

So if anyone has any idea what the correct and easy/normal way to trim this aluminum is, please help me out. This drove me crazy and I can't do it anymore in the future. There's got to be a better way.

David theres a aluminum "cutting fluid" you can use instead of WD40,
its made to do exactly what you want, keep the aluminum from melting,

i use it on my mill and lathe, but for the life of me here in the house i cant remember the mame,
its in a green can,
A-1 fluid,,,i think its called,
drip this stuff on your aluminum in front of you as you go,
but if your using a small diam. lam bitt the things to small, and youll
need to go slow,,,even P-Lam cloggs the small bitts,
if you can cut close with a jig-saw so the bitts only cleaning up the edge,,,just like P-Lam,
itl come out better,

just my opinion,
20yrs cabnets/kitchens,
5 yrs, machinest--self-taught
6months at a welder

johnp

[toypusher]

Not quite on the subject, but I need help with aluminum. I'm in southcentral PA and thought that I had an aluminum supplier, but that fell through. Does anyone in this area know a good supplier that I can get 4X10 or 4X12 aluminum from??

HELP! PLEASE!

[David Grason]

Ok, here's an update on the aluminum problems I had.

I simply got a good fine toothed metal cutting blade for my Bosch saber saw and cut the alumimum reasonably close to the final destination. Then I replaced my laminate cutter bit with the old style before they all got fancdy schmancy with bearings and such. This bit was $9.95 compared to the almost $30 of the others. It has only one cutting surface so it only takes one nibble per revolution as opposed to 3 per rev on the others. I put a little paste wax on the wood surfaces that the bit would be pressing against, slowed the speed control to as slow as it would go and then I took my time. It worked absolutely perfectly. I couldn't have asked for better results.

[fornesto]

I haven't noticed a speed control on my cheapo B&D Router. How else could I slow the speed? Through a voltage dropper? What? Where?

Thanks

[Geron]

I haven't noticed a speed control on my cheapo B&D Router. How else could I slow the speed? Through a voltage dropper? What? Where?

Thanks

Check this out.
http://www.harborfreight.com/cpi/ctaf/D ... mber=43060

Geron