aluminum

[jkeithrussell]

I took a first stab at making a segmented pen last night. It was a simple design based on one of the tutorials in the library, only I added some thin strips of aluminum between the sections. Basically took a Holly blank and a Purpleheart blank, stacked them, cut curved shapes on each end, swapped the pieces, and sandwiched a thin slice of aluminum.

I got in a hurry and it didn't work out right. The main problem I had was that my tools kept catching on the aluminum which caused the aluminum to bend back a little bit in several places. I suspect that the cause is simply not giving the segmented blank enough time to set up. The aluminum sheet that I used was .008 thickness. Is that too thick? I picked it up at Ace. It feels considerably thicker than a soda can, but it doesn't look thicker than others that are posted here.

Thoughts?

 

[CaptG]

Without seeing the results, my guess would be you need a sharper tool, more rpm and lighter cuts.

 

[TribalRR]

I am also guessing that you need to sharpen your tools. I have had that happen with inlays because the "pocket" wasn't filled enough, but never with a lamination... Perhaps the two wooden pieces are not mating like they should? I could see this happening if you had a gap. I don't think the thickness would matter, I've used many up to 1/8" pieces of aluminium.

 

[ribanett]

The aluminum sheet that I used was .008 thickness. Is that too thick? I picked it up at Ace. It feels considerably thicker than a soda can, but it doesn't look thicker than others that are posted here.

Thoughts?

The aluminum is not too thick. I used shim stock from NAPA, have turned 0.010" with no problem. Sounds like you are taking to big of a bite while turning. Use very light cuts or you will tear the segments out DNAMHIKT.

BTW I post a draft for my segmenting tutorial in this forum titled Six-segment Tutorial

Hope this helps

 

[jkeithrussell]

Thanks for the info. I did also have a blow-out of one of the small sections that looks like it was caused by a catch on the aluminum, so it looks like I didn't keep a sharp enough edge. I sharpened as well as I can before I started, but I didn't remember to stop and touch them up. I'll try again this weekend. Thanks.

 

[VisExp]

Hi Keith, this is Keith :biggrin:

I don't think 0.008" is to thick. If it felt "considerably thicker" than a coke can it may not have been 0.008" as a soda can is 0.007". Regardless I don't think that was the problem. As others have mentioned sharp tools and a light touch are needed.

Another thing I find is the direction of the cut. On my Circles in a Forest design I have to be pretty careful about the direction of the cut as I cross the inlays. I try and cut "with the grain" of the inlay. In other words I try and cut in the same direction as the metal is going (assuming the metal is not perpendicular to the blank). Cutting against the "grain" of the inlay increases the chance of the tool to dig under the metal and lift it up.

Obviously this is not always possible depending on the design.

Hope this make sense.

 

[rherrell]

Don't forget the alloy of the aluminum. Not all aluminum is created equal so if the stuff you have is too hard that could also cause problems. Did it hold it's shape EASILY when you tried to form it or did it have a little "spring" to it? "Spring back" is an indication of a harder alloy.

 

[Roy_Quast]

Hi Keith....
Sharp tools and a light cut might get you there but here is another way you might try. Use your gouge or skew to turn the blank just till it's round. Then from there use nothing but sandpaper....something around a 36 grit. Even with sandpaper, watch the heat buildup. If it's getting too hot, stop for a few minutes and let it cool down. I have used this method on copper, brass, and aluminum with no blowouts.

 

[UKpenmaker]

I too don't think the thickness of the aluminium is any problem. I have done some with quite thick grade (can't remember how thick, but a lot more than a can).



Are you roughing up the surface of the aluminium weel before doing the glue up? I normally use 80 grade paper. Then i glue up with thick CA and leave for about 20 min in the clamps.

I have found that when drilling can cause problems, try to avoid getting the blank too hot when drilling as it can make the wood pop a little from the aluminium in places. So i wrap the blank in adhesive strong tape and use a very sharp bit, and drill as if doing a acrylic blank, just take lots of small drill cuts.

 

[leehljp]

I have found that when drilling can cause problems, try to avoid getting the blank too hot when drilling as it can make the wood pop a little from the aluminium in places. So i wrap the blank in adhesive strong tape and use a very sharp bit, and drill as if doing a acrylic blank, just take lots of small drill cuts.

Eagle got me started with segments, and seeing his picts, he did something like what you did except - he wrapped cord around the blank fairly tight and CA'ed the cord, drilled and then turned, IIRC specifically.

In most cases, to be successful without blowouts, or if you have a special blank and you CANNOT afford to have it blow out, or would do ANYTHING to prevent it from blowing out or separating, - bind it with something VERY tight and CA it. Drill and then turn. We can "chance" to have it done quickly, or spend time to increase the odds considerably that it will be done intact a few minutes later.

 

[plcamp]

0.008" is pretty thin and I would suspect that is causing a big share of the problem, sharp tools are also a must.

I would suggest using alum from 1/32 to 1/8 inch thick for your next try.

Paul Camp
NE Indiana

 

[jkeithrussell]

Thanks for all the pointers. I'll try again tomorrow.