Fabricating from aluminum

[Drobie]

The bulkhead in the shaft thread brings up some other questions regarding fabrication with aluminum.

1. How do you join two pieces....solder or JB Weld?

2. What kind of blade do you use to cut aluminum?

Any other tips?

[AndyKunz]

I cut it differently depending on application and thickness. Shears work great if you can flatten it out afterwards. If no bending is permitted, I cut with a Dremel cut-off wheel (actually the Dubro cutoffs are better).

To join I either bolt together (skid fin to bracket, etc). THere was a recent thread on soldering/brazing them with stuff sold at the trade shows, but I don't like it for structural joins. To attach to something like the bulkhead, epoxy works great.

Andy

[eddieh]

Doug, I use a fine tooth blade in my bandsaw for cutting, (wear gloves) the metal does heat up a bit, and for joinong, I do braze it, I have made the strut and other bits with brazing the aluminum, on my cesa, (look at the post old cesa new hardware) I have had 30 cells in this boat and the strut held up fine, you can try it, JB weld will also work fine, but for me I think the brazing is fine and looks better too, cheers eddie

[vicman]

One more thing, if you are going to use a powered saw, you really need to lubricate the blade while cutting. Keeps heat down some and prevents damaging the saw blade. I have foun that for drilling and cutting alum., a nitro fuel works best for this, or you can use wax, bar soap, or a light oil, (none of which works as well as nitro fuel in keeping the blade sharp and cool)

vicman/v.m.p.

[Stano]

I find that on my saw It cuts better with a fewer tooth blade I use a 7 tooth per inch. with someone squirting some soapy water it will blaze thru it like wood. The guy I get my band saw blades from suggested to me to cut aluminum like you would wood. works pretty well for me I made a rudder the other day I will try and post a pic.

[Drobie]

What is brazing?

[eddieh]

Doug, Brazing is another term for Gas welding, I use a small micro torch but have also done this with a regular propane torch from home depot, if you try it, try to use mapp gas as it is a little hotter, same bottle though, here's a site might explain it better if your interested, hope it helps
http://www.tinmantech.com/html/faq__brazing_vs__soldering__te.html

[RCBoatingNewbie]

When I need to do LARGE, LONG, STRAIGHT cuts in aluminum, I use a table saw when possible. Nothing fancy, just a regular ole' blade in it, but, MOVE SLOWLY! The biggest problems are: 1) noise- VERY loud to do this. 2) blade width. With common wood cutting blades (the kind I like to destroy with aluminum), a large portion is taken out, an 1/8" is not uncommon. 3) this is pretty hazardous. Aside from the flying aluminum chips, if that piece of aluminum gets flung, watch out!!!

I've cut aluminum over 1/4" thick this way (take your time, though!). Another benefit, you get these neat shiny flakes of aluminum you can find all over your house for months later. I still haven't come up with a use for them, but they sure are nifty! LOL

The benefit of the "table saw" method is the speed and clean straight lines. I can rip some aluminum pretty fast with a high hp saw and a fresh blade.

For smaller cuts, I do the Dremel disc thing.

In all scenarios, the cuts aren't perfectly clean- however, the slower I go, the smoother the cuts are.

In finishing up, I use a combination of an X-acto knife, a sanding wheel on the Dremel, and plain old sand paper.

For fine brass sheet, I'll cut with heavy scissors (utility kind). From another post, yeah, this is problematic in that it bends the metal.

I've thought about one of those "paper slicer" thingies for thin sheet metal, with a table, squared edge, and large knife blade pulled down by a handle. I'd imagine it wouldn't bend the metal, and would make clean, perfectly straight cuts.

I am NOT a fan of hacksaw blades- they just don't quite give me the accuracy I'm looking for- they bend, they twist, and at shallow angles, they seem to take forever.

I don't have any experience with welding of any type, so I'm one of the "bolt it" guys.

[eddieh]

RC, Tablesaw huh??? I have never tried that, and I am unlikely to do so, man that does sound on the far side of sane, I know your careful, but man oh man, If I wanted to use something like a tablesaw, I would get myself one of those wetdry tile saws. a thought though if you were going to try it would be to turn the blade around, I do this for cutting paneling etc, and gets a smoother cut. The paper cutter will bend the sheetmetal too, as it is really a glorified scissor, starts at one end and moves down the length of the material, the only benefit is yes it can be really straight, try a nibbler from radioshack, or from harborfreight, depending on what you want to spend it can even be powered, the manual one is fairly cheap, and you get smooth cuts and if you can follow a scribed line very straight. I cut all my thicker stuff on the bandsaw, I feel it's safer as it is pulling the work into the table, a table saw is trying to shoot it back on you, if you needed a really straight cut, I would buy from a supplier instead of the dyi shops, the supplier would probably cut it for you, he has the right kit, anyway a couple of thoughts, cheers eddie

[RCBoatingNewbie]

Originally posted by Eddieh
RC, Tablesaw huh??? I have never tried that, and I am unlikely to do so, man that does sound on the far side of sane, I know your careful...

It's not quite the far side of sanity (I think!). I get a bit nervous whenever I start pushing a piece of aluminum at the blade. When it comes to spinning blades with unforgiving cutting surfaces, I turn into a big hairy slug at .5 mph.

All it takes is some cohones, and a slow, steady hand.

The only time I get nervous is in the slight pushes I make during a cut- when the blade carves a chunk, and hot pieces hit me in the face (kidding, they usually just hit my shirt! LOL)

[Drobie]

I can attest to the table saw option.

I just put a nice slice in an aluminum miter guage extension when I was paying more attention to the piece being cut and my fingers than where the guage was.

It cut it like butter. I just don't like to get my fingers in there with small pieces.

[eddieh]

RC/Doug, to each his own, Cahones huh, I am a married man, my wife keeps those , LMAO anyway , I take only the risks I have to, just don't want to see anything happen to you guys,, cheers eddie

[J Tracey]

I work with alum all the time. If you do not have the right tools you have to ask yourself "H ow much will I save if I loose a finger?" Without the proper tools working metal can be dangerous. A metal cutting band saw can be gotten from Harbor Freight for under $200. The blade does not have a high speed, and with a rip fence it will make clean cuts.

[RCBoatingNewbie]

Trust me, I'm not going to throw a finger away! :) I usually set the blade very steep (height adjustment) to have a high downward force on the metal. I keep a firm grip on the metal, but, with the constant thought- I'd rather let the metal get chewed up before my fingers. If I wanted to be even more safe, I could swap out the blade for something with much much much smaller teeth (if I do much more aluminum work, I'll probably do just that!) to get more of a grind than a chop.

I'm a meticulous person, not some crazed lunatic with a piece of metal and a saw! LOL

The worst "accident" I've ever had was with a pair of pliers, trying to fit a multi-conductor cable into a hermetically sealed connector. I got a scrape on my left hand. That was in 1994. I haven't broken a single bone in my body in my entire life. I come from a long line of builders who've worked with power tools their entire lives, no loss of limbs or fingers. Maybe it's genetic, who knows.

I can say, whatever tool you're working with has the ability to inflict serious harm under the right circumstances. It comes down to respecting what a tool can do, not fearing what it could do.

Honestly, the feed rate I use when cutting metal puts me at less risk than ripping a 2x4 in a few seconds. I get more nervous ripping down pieces of wood than I do working with aluminum- something about the speed at which the hands need to work.

The worst thing I'd expect in cutting aluminum on a table saw would be for the saw to grab the metal, and try to suck it down. The metal would get pulled from my fingertips.

Anyone want to see a picture of a big aluminum heat sink I ripped down on a table saw? :)

There's a lot to be said for having the right tool for a given job, and I'm not denying that. But, I'm also saying, with enough care and caution, some other tools can get the job done. Trust me, if I had the money, I'd own every tool in sight!

It's not what you've got, it's how you use it. (LOL)

[eddieh]

RC, I get the message, your being safe, OK, anyway getting back to aluminum, anyone ever try to cut aluminum, on a jig saw?? I make a lot of scale fittings and thought it would be cool, with a blade that can cut very minute, slots etc, anyway , I just got a rotary table for my mini mill, and I have to say, man it looks good sitting on that work bench, now if I only knew how to use it, LOL, two of the best tools I have bought have been the mini-mill from grizzly and the mini lathe from harbour freight, It's a whole new learning experience, and I have to say you get tremendous satisfaction, when you take the quality of your hardware up a notch, Got rain out saturday for my 18 cell test run, I guess I'll try next weekend,
keep the shiny side up, and the wetted side down, cheers eddie

[T.S.Davis]

I used my Crafstman hand held jig saw to cut aluminum. I works but is noisey and forget about a tight radius. Anybody ever try one of those RotoZip saws? They look like they would be similar to a jig saw. I never thought about cutting metal with one.

Terry

[eddieh]

Terry, I think you would be ok with a rotozip and the right blade, the thing is to have it clamped because the heat build up is incredible, but I have tried the rotozip attachment on my dremel less then impressed, as far as the jigsaw, what I meant was a scroll saw, (like the dremel/craftsmen) I often use the wrong terminology for tools, I thought the hand held was called a saber saw, who knows, I really have good results with my bandsaw, I wanted to do more intricate cuts mostly for looks, cheers eddie

[Pete B.]

I think a rotozip would work fine w/the right blade. Just build a fence around your work and clamp it down. The rotozip has so much power it is hard to follow a line or patern with out one, always cut in the direction the blade spins this will use the power from the tool to keep it against the fence. Practice on scraps first!

just my own experience


Pete

[T.S.Davis]

Eddieh,

Tracked down my saw and sure enough you were right. Craftsman does call that a thing Sabre Saw. Never payed attention (duhhh). I've been using it (with a fine tooth blade)to get my pieces close and then use the dremel to get them the rest of the way. Both are not fun when you want to cut a radius. How does the band saw do with radius cuts?

Terry

[eddieh]

Terry, out side fine, inside not so fine, I have the delta small bandsaw, and when I use a fine tooth blade not bad, but I wouldn't show it to my shop teacher, now that I got the mill , I do the rough cut as close as possible and then finish off with the mill, saber saw jig saw, it's all good LOL, cheers eddie

[airdevil85]

for long, straight cuts, try clamping a board, or table saw fence to the band saw's table that is parallel to the blade
I have included a rough drwaing

[eddieh]

one tip i do have for cutting rod or tubing in halh is to drill an appropriate size hole through a block of wood, then push the block dead center on the hole into the bandsaw, the block will act as an additional guide block, then feed the tubing or rod through the hole, perfect half rounds for trim etc, (scale boats) very nice....cheers eddie