Aluminum Fairing Tutorial

[DY]

Aluminum Fairings Tutorial!! ( June 28, 2008 )

I'm bored, might as well type this up. theres probably lots of typos, I'll check for them later.

Material:

• 2mm aluminum sheet (5000 series, if you want to weld)
• Cardboard and paper
• Sharpies
• Jigsaw, Metal jigsaw blades
• Angle grinder, Sanding disk
• Drill and drill bits
• Rubber hammer
• Zinc Chromate Primer (conversion coating)
• Whatever other paint you want to use.

How to:
Alright, so this weekend I decided to make some tank covers for my bike. This tutorial will explain how to make fairings out of aluminum sheets.

NOTE: I also tried using plastic to do this but it is just a huge PITA. It is almost impossible to thermoform a clean bend without a mold as some places heat up more than the other. I also cracked and chipped it in many places when I wasn’t careful with the jigsaw. Aluminum is light, soft yet strong and extremely easy to work with. However, it is hard to make compound radius curves.

STEP 1:
Make a cardboard template of what you want to make.

Here you can see my rough template. Consider the bends you have to make, where you’re going to mount it, and of course, how it would look. Feel free to bend this piece of card board however you like, as long as it’s in one piece.

STEP 2:

Take the cardboard off, and trace the design to paper. Cut it out with a scissor along the INSIDE edge.

Round off the edges, and make it look pretty now because this is how you’re going to cut you’re aluminum sheet by. If you can, make the template bigger than the piece you want. With metal, it’s easy to remove material but it’s hard to put it back. Make a multi piece template if you are going to be welding it.

STEP 3:

Trace design on to aluminum sheet.



STEP 4:

Grab your jigsaw and cut away. Please wear some safety glasses. I found it easier to the section out of big sheet first, like below.

Here we go, nicely cut off. The edges aren’t really straight yet, and the shape is still quite rough. No worries though, we’ll fix it up later.


STEP 5:
Bend the piece to shape. This is probably hardest thing to do with aluminum. I find it easier to bend a bit at a time, keep referring back to your bike. Make it fit really well because aluminum doesn’t flex as well as plastic. Drill mounting holes bigger than they need to be. Use a sharpie and draw the line where you want it to bend and draw arrows to remind yourself of the bend direction. I used a vise and a soft hammer to shape my piece.

Smooth meant I have to smooth the part out a bit more. The lines with the arrows show where I want to bend.

Bend with the vice if you can.

STEP 6:
After all thebending is done, check fit again with your bike. If you are happy with it, then get out your grinder and sanding wheel. Using the vice and the hammer can really put some scratches and dents into your piece. Aluminum is really soft, so a sanding disk has no problem smoothing it out. Go over with 80grit sandpaper to get it smooth. Get rid of the burrs and sharp edges with the 80 grit.

STEP 7:
If you want to polish, then proceed to polishing. If you want to paint then you need to prime it with a special primer. Normal paint doesn’t stick to aluminum very well, so you need to use a conversion coating. The most common being zinc chromate. CT sells this stuff and is actually decent quality.

Be careful though, this stuff STINKS! A mask is a must.

Here we go…..apply a few coats and sanding down with 400 grits. This stuff fills scratches amazingly well for some reason.

EDIT: Color coat should go on as soon as the primer is dry to touch (15 to 30 min). Apparently, the primer is very moisture sensitive and leaving for longer and the paint won't stick. (thanks Dropgear!)

FINAL STEP:
PAINT!!!!
I decided to paint mine flat black because I don’t want to disturb the color theme and this black just looks real good on metal.

Left and right covers done. BTW: if the parts you are doing are symmetric then just flip the template over for a perfect duplicate.

Hope that helps! Again, sorry for the crappy picture quality. My camera is really messing up on me.

[andr01dm]

I made some aluminium brackets for lowering my bike's seat and found that bending and shaping was made much easier by annealing the metal first. That is heating it up with a torch and then letting it cool slowly to room temp. It will reduce the aluminium's strength a little, but if it's being used for fairings or parts that don't get much stress it shouldn't be a problem.

Thank you for the information on the zinc chromate primer. I'll have to give that a try before I paint next time. ^_^

-[a]-

[dropgear]

awesome, thanks for this insight.

where did you source the aluminum from?

[DY]

Metal Supermarket in Oakville. Right on Speers Rd.

[RockerGuy]

wow man, u should be bored more often. I vote for a DIY section and have this added.

[CanadianNinja]

very nice fabrication job! i was thinking of doing something like this before i decided to restore my old fairings instead. got any pics of these pieces mounted on the bike?

[DY]

wow man, u should be bored more often. I vote for a DIY section and have this added.

lol, I was gonna do a tutorial for valve adjustment a while back but didn't wanna get my camera greasy. I'll try to do a small tutorial once a week if this kind of stuff is some what helpful. A DIY section would be great too, theres lots of articles in this section that should be stickied. Maybe this DIY thing should go under technical forum, like the Insurance Specialist page.

anyhow,

here are some pics of the tank covers on the bike. I also just finished spraying my tail this weekend. Duplicolor rules! again my camera sucks.

[dropgear]

yeah, that's pretty amazing. well done!

pretty much my exact need as well ... except, maybe, in "shiny"

[CanadianNinja]

looks good, the fit makes it look almost OEM

[dropgear]

DY, i bought two pieces of aluminum, and have finished the mods to my seat/lights, and all of that tail stuff.

Living with 5 other students means that I don't really have the space to get a lot things done ... so this will be slow.

[DY]

DY, i bought two pieces of aluminum, and have finished the mods to my seat/lights, and all of that tail stuff.

Living with 5 other students means that I don't really have the space to get a lot things done ... so this will be slow.

Awesome! glad this is some help.

Please post pics once done!

[shaf]

Awesome job!! Looks great!

[dropgear]

that black stuff under the seat is what i want to make happen ...

please ignore the other gimp'ing, like the white sticker placeholders and the photochopped wall

[ZXGreenR]

so that's how you did it. Saw it in person this morning, looks awesome, very clean! good job again.

[dropgear]

hey man .. followed your tutorial thus far .. have to buy some zinc chromate now.

i'm finding that taking the edges down is done best by handheld paper, rather than with a dremel or whatnot. i wasted a lot of time shaping the edges with the dremel today .. the aluminum is sanding really easily.

I was worried that 2mm was going to be too thick to work with: definitely not! Once you have it down to a manageable size, the rigidity of the 2mm trumps any other property (such as being able to bend it easily, etc.)

Also, be careful with your paint job on your tank/frame/etc. when test-fitting I have a few light scratches now that didn't exist before. Such is the cost of DIY.

[DY]

Good stuff man. I saw your pics on the other thread. you can by the zinc chromate stuff at CT.

[dropgear]

Well, initial failure in the paint job.

Applied Zinc Chromate, let dry overnight. Good results (though it wasn't very ... scratch resistant). Tried black paint: some bubbling/cracking in points after applying a Duplicolour top-coat! Shoot. I did some reading and it appears that the chemicals are the issue. Possibly my selection of paint, and the fact that I left it overnight. Should have done it right after the zinc was dry to the touch.

Apparently Zinc Chromate is not the ideal primer for aluminum in most cases. And it's very sensitive to moisture ... even the moisture in the $5 latex Duplicolor paint.

The issue is the way that aluminum oxidises. The oxidised particles prevent things from sticking, create bubbles, and draws moisture in.

A solution that I saw posted on several forums/websites:

Maroon Scotchbrite pads are the best way to remove oxidation, either the hand pads, or the drill motor mounted "Surface Conditioning" pads. Degreasing and oxide removal can be combined.

Most auto parts stores can at least order self-etching single part non-chromate primers in spray cans or quarts for brushing with a foam brush (problematic, holidays are badddd), roller-brushing (roll an even coat on and tip it with a foam brush, better) dipping or spraying. NAPA carries Martin Senour 7220. Marhyde makes another one. These are one part alkyd systems that have very low health risks, a simple particle respirator is semi-adequate protection. It's crucial to apply the primer as soon as the surface is dry from the final rinse. A mild solvent wipe (alcohol) can be used to speed up drying.

There are some simple alternatives .. available at Canadian Tire.

- Duplicolor also has a one-shot solution in the form of aluminum rim paint. Sand down, degrease, rinse well, and apply quickly after drying completely. Not super pretty, but very abrasion/winter resistant. I don't even know if they make "black."

- Mothers Adhesion Promoter. Sand, degrease, rinse, apply promoter, wait 5-10 mins (max), apply paint. Apparently somewhat tricky with the timing, yields mixed results, but lets you apply really pretty paint.

[DY]

Well, initial failure in the paint job.

Applied Zinc Chromate, let dry overnight. Good results (though it wasn't very ... scratch resistant). Tried black paint: some bubbling/cracking in points after applying a Duplicolour top-coat! Shoot. I did some reading and it appears that the chemicals are the issue. Possibly my selection of paint, and the fact that I left it overnight. Should have done it right after the zinc was dry to the touch.

Apparently Zinc Chromate is not the ideal primer for aluminum in most cases. And it's very sensitive to moisture ... even the moisture in the $5 latex Duplicolor paint.

The issue is the way that aluminum oxidises. The oxidised particles prevent things from sticking, create bubbles, and draws moisture in.

A solution that I saw posted on several forums/websites:



There are some simple alternatives .. available at Canadian Tire.

- Duplicolor also has a one-shot solution in the form of aluminum rim paint. Sand down, degrease, rinse well, and apply quickly after drying completely. Not super pretty, but very abrasion/winter resistant. I don't even know if they make "black."

- Mothers Adhesion Promoter. Sand, degrease, rinse, apply promoter, wait 5-10 mins (max), apply paint. Apparently somewhat tricky with the timing, yields mixed results, but lets you apply really pretty paint.

wow that weird. I had no issues what so ever with my primer. Could be that I used a different kind of top coat. But did you sand the aluminum before paint? the primer needs something to stick onto, I went over mine with 80 grit and it stuck fine. Yes, I did shoot my paint right after it dried.

I had the same issue with the paint not sticking when I tried painting semi polished aluminum. the clear coat just peeled right off.

My paint actually held up incredibly good. Even after my slide last week, the aluminum exhaust support was bent whack out of shape and somehow the paint stuck right on. Even After I hammered it back, I only had to shoot black over it.

I dunno, adhesion promoter is sort of like glue which sticks better but chromate conversion is what they use in the industry before painting aluminum.

anyhow, if you find something that works better please post it here.

[dropgear]

wow that weird. I had no issues what so ever with my primer. Could be that I used a different kind of top coat. But did you sand the aluminum before paint? the primer needs something to stick onto, I went over mine with 80 grit and it stuck fine. Yes, I did shoot my paint right after it dried.

I had the same issue with the paint not sticking when I tried painting semi polished aluminum. the clear coat just peeled right off.

Yeah I sanded the living hell out of the surface .. but with a higher grit (quite smooth to the touch). The zinc chromate held up well .. I'm just thinking that I left too much time: basically let the aluminum oxidise overnight through the zinc chromate .. so when I applied paint, the whole thing went to hell.

I spot painted the underside of the fairing the night before, as a test, and that spot held up very well. So that's why I was surprised with the results today.

Seems like the additional detail to your process here is: spray the paint on as soon as the zinc is dry to the touch. Will test that and report back.

[DY]

Yeah I sanded the living hell out of the surface .. but with a higher grit (quite smooth to the touch). The zinc chromate held up well .. I'm just thinking that I left too much time: basically let the aluminum oxidise overnight through the zinc chromate .. so when I applied paint, the whole thing went to hell.

I spot painted the underside of the fairing the night before, as a test, and that spot held up very well. So that's why I was surprised with the results today.

Seems like the additional detail to your process here is: spray the paint on as soon as the zinc is dry to the touch. Will test that and report back.

ya thats probably why, sorry I didn't mention it before. I never thought it was a bit deal. I'll edit the instructions.