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.040 aluminum panel edge trimming

PostPosted: Wed Aug 19, 2015 11:26 pm
by noseoil
I'm going to be using some .040 pre-finished aluminum for the skin on my build & will use a router with a 1/2" flush-cut bearing bit for the final pass. My question after reading about other people's experience is, what's the best way to trim the sides down to get them close enough for the finish pass with the router?

Would it be best to use a power shear or nibbler with the side held in place and glued at the edges prior to trimming? Is it better to hold the skin in place first, mark with a magic marker on the back side, take the side off, lay it face down & then trim it close to the line before putting it in place?

I'm just not sure what's the easiest, best & simplest way to do this. I know the router is the best way to get a good fit, but it isn't the best at removing a large slice of panel. It's better used as a finish tool than a metal hog. I have a sabre saw I can use, but I don't have sheet metal tools.

Appreciate your advice & comments. Thanks, tim

Re: .040 aluminum panel edge trimming

PostPosted: Thu Aug 20, 2015 12:00 am
by tony.latham
I mark my sides with my pattern and cut close with a sabre saw and a fine toothed metal bit. After it's on the side of the cabin, I route it flush.

I bought a pneumatic nibbler and don't care for it.

When you run the router, protect the aluminum with blue tape. Otherwise the tool is going to want to drag aluminum burrs across the finish.

T

Re: .040 aluminum panel edge trimming

PostPosted: Thu Aug 20, 2015 8:49 am
by aggie79
tony.latham wrote:I mark my sides with my pattern and cut close with a sabre saw and a fine toothed metal bit. After it's on the side of the cabin, I route it flush.

I bought a pneumatic nibbler and don't care for it.

When you run the router, protect the aluminum with blue tape. Otherwise the tool is going to want to drag aluminum burrs across the finish.

T


I feel the same as Tony. I have an electric nibbler and it didn't cut the aluminum very well. For the sidewall aluminum I used the template that I made to cut the plywood "framing", traced the profile on the aluminum, and cut it with a jig saw. Because the template dimension was did not include the 1/8" thickness of the front, roof, and hatch plywood skins, I didn't need to route the edges. (Plus, I think it is a good idea to leave some clearance at the edges to minimize oil-canning.)

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For the top aluminum, I just cut it 1/8" shy of the teardrop width using the jig saw.

FYI - I used a perimeter bead of sealant around the profile and openings. Here is picture of the aluminum applied showing sealant squeeze-out and the clearances at the edges.

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Re: .040 aluminum panel edge trimming

PostPosted: Thu Aug 20, 2015 9:47 am
by halfdome, Danny
Tim, When routing the .040 aluminum either use a speed controller or a different bit than a 1/2" flush trimming bit.
In my experience the 1/2" two flutted bit will melt the aluminum so I went with a Freud 42-118 3/4-Inch Diameter 2-Flute Flush Trimming Router Bit with 1/2-Inch Shank.
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I've found other uses for this great router bit so I ended up buying a second one.
A speed controller might also help keep your 1/2" bit from melting the aluminum.
I use a pneumatic shear to pre cut the aluminum 1/2" over sized on the bench.
:D Danny

Re: .040 aluminum panel edge trimming

PostPosted: Thu Aug 20, 2015 1:52 pm
by Graniterich
What type of router do you use?

Re: .040 aluminum panel edge trimming

PostPosted: Thu Aug 20, 2015 3:46 pm
by halfdome, Danny
Graniterich wrote:What type of router do you use?

A 1 1/2 hp Porter Cable.
They come with a 1/4" & 1/2" collet.
:D Danny

Re: .040 aluminum panel edge trimming

PostPosted: Thu Aug 20, 2015 5:22 pm
by dales133
This is a realy great little router with a heap of accessories including a plunge router base.
It a solid aluminium and has that old school makita quality.
https://www.google.com.au/search?site=& ... ydjoKLY130.
I effortlessly trimmed some 1.6mm aluminium with it,its varriable speed too

Re: .040 aluminum panel edge trimming

PostPosted: Thu Aug 20, 2015 7:00 pm
by halfdome, Danny
I have one too, nice router for small jobs.
I bought it to cut the door opening through the aluminum after I glued it onto the sides.
Home Depot has them for about a hundred bucks.
Have a 1/4" double bearing bit for the task to keep waste to a minimal, kind of expensive ( about $50.00) though.
:D Danny

Re: .040 aluminum panel edge trimming

PostPosted: Fri Aug 21, 2015 7:18 am
by noseoil
It sounds like I need to pre-trim the aluminum to match the profile within about 1/8" of the roof edge. I was thinking about a nibbler for this, but since I have the saber saw already, that's what I'll use for the cuts. I'll have the side cut itself, plus a door & window opening on each side to do. The driver's side also has the power inlet, passenger side has the snorkel for the battery box to trim out as well. I also need to do the wires on both sides, markers, porch lights.

I just have an old Ryobi 151 router & no speed controller, so that's what I plan on using. If I get fairly close with the trim (1/8"), it should be OK to use. I saw recently in one of the threads where a small amount of oil on the edge helps with the chips & melting to keep the cutter clear. Was also thinking about using some bee's wax to do the same thing for the cut. Have to play with that one first to see if it helps or hurts. I'm also considering using something like Sikaflex to glue the edges in place first, (the outside perimeter, doors, windows & other penetrations) prior to doing a trim with the router. I'll tape the edges so I don't scratch up the finish when running the pass.

So far things are going pretty well & I don't want to blow it this close to the end. As always, thanks for the input on my questions guys, much appreciated. Will take pictures when it's time & post them to the build thread when I do it.

Re: .040 aluminum panel edge trimming

PostPosted: Fri Aug 21, 2015 7:41 am
by dales133
Sikaflex routes fine just so you know.
All the areas i flushtrimed on my side profiles that were sikaflexed on cut perfectly with no dags or tears

Re: .040 aluminum panel edge trimming

PostPosted: Fri Aug 21, 2015 6:04 pm
by Graniterich
It seems like when cutting a door my 2 horse router might be awkward. Could I use a 1/4 inch trim router?

Re: .040 aluminum panel edge trimming

PostPosted: Fri Aug 21, 2015 6:31 pm
by dales133
Graniterich wrote:It seems like when cutting a door my 2 horse router might be awkward. Could I use a 1/4 inch trim router?

Yep,if its a decent one.
I currently only own my little makita and i cut my hatch ribs out of 1 1/2 hardwood then bullnosed them with it,youll be fine

Re: .040 aluminum panel edge trimming

PostPosted: Sat Aug 22, 2015 5:40 pm
by tony.latham
I just have an old Ryobi 151 router & no speed controller, so that's what I plan on using.


It'll work just fine. You may want extra eye protection. 8) It's a dirty job.


T

Re: .040 aluminum panel edge trimming

PostPosted: Wed Sep 09, 2015 8:00 am
by noseoil
A follow-up question for the skin, what about the trim & curves I have to form? I have the front radius (24") & the rear one (30"). Dead-blow hammer or is a torch better to soften the aluminum first? I have roof trim & thin-edge molding to lay on the curves. Just don't know how soft this stuff is to work with and how prone to kinking it will end up being. Thanks, tim

Re: .040 aluminum panel edge trimming

PostPosted: Wed Sep 09, 2015 9:23 am
by tony.latham
Tim

All of the trim that I've used has been soft and I've purchased from three different retailers.

I set the first screw and work from there. If the curve is too tight to be bent by hand, I use gentle taps with a deadblow. Too aggressive and you'll dent it. I have not used the plastic insert type. That stuff could be prone to damage with a hammer.

I fit the trim, remove, lay the seal down, and reapply.

T