proper tool for trimming aluminum sheet from sides?

[belay70]

OK Ive got the sides up with a benroy type of shape in mind.



Instead of actual .032 alum sheet, Ive acquired some 1/8 inch composite aluminum/plastic panels. They are basically .050 alum on both sides, with plastic resin sandwiched in between. Total thickness is 1/8 inch, and these are usually used to cover the outside of newer Chevy dealerships. Gotta love craigslist!

Anyway, I had planned on using my router with an as yet unknown type of bit to reproduce the radius curves already in the 1/2 birch plywood sides. The bit would need some sort of guide, so I wouldnt have any danger of cutting into my plywood sides, as I trim the alum panels. Anyone know of such a bit or a different tool? Ive also considered using my Zip tool, but again, need the proper bit/attachment. I would just lay the alum panels flat and cut the same curves with my jigsaw, but I really hate how wobbly and prone to miscuts that jigsaw is. Id rather use something that will trace the existing curve, so I dont have mistakes.

Wondering how others have gone about this.....my first build I glued then cut the panels with the sides all in one shot, but for various reasons didnt want to do that this time.

[Tinbasher]

It is called an Edge Trimming or Flush Trimming router bit depending on the maker. Trend, Rockler and just about everybody lose does them.

[citylights]

It is called an Edge Trimming or Flush Trimming router bit depending on the maker. Trend, Rockler and just about everybody lose does them.

They have a roller bearing on one side that will ride on your plywood sidewall while the blades cut the aluminum. 1/4 inch sandwich aluminum? Great find. Might be a little more difficult to cut than regular. Take it slow and careful. Wear eye protection.

[aggie79]

Trace the outline onto the composite sheet. Use the jigsaw to cut within about 1/8" the outline/final cut line. Then install the composite sheet and use a carbide pattern/template bit in your router trim it flush. If your aluminum does not have plastic protective sheeting, put down some masking tape to keep from scratching the surface. Also, wear goggles. The hot aluminum "bits" fly everywhere when you trim to final fit.

[alaska teardrop]

Instead of actual .032 alum sheet, Ive acquired some 1/8 inch composite aluminum/plastic panels. They are basically .050 alum on both sides, with plastic resin sandwiched in between. Total thickness is 1/8 inch, and these are usually used to cover the outside of newer Chevy dealerships. Gotta love craigslist!

Michael, Here is a link to Tom's recent thread about using ACM panels: viewtopic.php?f=21&t=56753

Not sure that this would make any difference in your plans to use ACM panels, but I would like to point out that the aluminum is probably .050 millimeters rather than .050 inches & that it is about twice the weight of .032" aluminum sheet.

Fred

[Tinbasher]

Also, wear goggles. The hot aluminum "bits" fly everywhere when you trim to final fit.

The cutter creates tiny crescent shaped bits that are sharp as needles and get everywhere, even into the soles of your boots. Then when you walk on carpet you stick to it like Velcro which made me very popular with Mrs Tinbasher as I picked up carpet tiles like big snowshoes

[belay70]

sorry, yes, they are .050 mm, not inches. Not sure why I said inches....and thx for the link. Im simply using gorilla glue, lightly, to adhere the panel to the birch plywood sides, with 3 inch exterior screws along the bottom, where it attaches to the floor/bed. Then I'll cover those up with some trim. Did that with my first build and it worked fine. Been through some hot days and cool nights and about 5000 miles so far, and havent noticed any issues from movement.

[belay70]

Also, small question while I have your attention - Ive used the normal dark brown gorilla glue - polyurethane glue I think. Not crazy about the way it expands and foams. Does everyone use that, or can I get away with the GG wood glue variant?

[atahoekid]

I've only used the original GG and yes it does foam quite a bit. Bt you can lessen the foaming by reducing the amount of water. Instead of spraying the opposing material, try wiping the material with a lightly damp cloth. You might also try fogging or misting the airspace above the material. Less water means less foam

[Bogo]

Also, wear goggles. The hot aluminum "bits" fly everywhere when you trim to final fit.

The cutter creates tiny crescent shaped bits that are sharp as needles and get everywhere, even into the soles of your boots. Then when you walk on carpet you stick to it like Velcro which made me very popular with Mrs Tinbasher as I picked up carpet tiles like big snowshoes

Get the shop vac out, and have somebody vacuum up the bits as they are generated.

[SLUG36]

make sure to sand and de-grease the aluminum to get better adhesion. the sanding creates a "tooth" or little scratches for the glue to grab onto. and de-grease with some type of paint thinner or brake parts cleaner. I mention this because unlike wood. your glue wont be able to soak into the aluminum. and the coarser the sand paper job on the aluminum, the better.