DIY Fairing for roof rack. Would like advice.

[Buliwyf]

45 degree angle aluminum.

A sheet of black fiberglass or black PVC would also work.

 

[R Thomas]

ABS and acrylic are much less expensive than Lexan, which is just a trade name for polycarbonate. They are also much more UV stable than Lexan and can be worked in the home shop more easily. I would pick ABS, then acrylic, with polycarbonate being the last choice unless it comes along cheap.

Jig saws do not work well, because they do not evacuate chips effectively. The chips get cut and recut, getting hotter with every cut and melting. Router bits work better when you can direct air at the cut to remove the chips. Up cut 2 flute carbide end mills work the best for cutting sheet. The spiral motion of the end mill removes the chips better. For getting a good radius and edge on the corners, cut the plastic slightly oversize and use a flush trim router bit with your wood template to finish the edges to shape. You can then radius the sharp edges with a orbital sander. Acrylic doesn't work well with traditionally shaped drill bits.

Polycarbonate / Lexan can be bent with a metal brake, but doesn't heat bend well. It absorbs moisture, which can make bubbles in the bend area if not dried out properly. Drying takes several days in a low humidity environment.

 

[rayra]

Nice idea, good placement and rounded corners.

I'd do it again in aluminum plate and use cap-head fasteners and bolt it directly into the rack tubes.

 

[doug720]

Here is the deflector on the rack I made. I welded tab's with captured nuts to make it easy.

It's quiet and works well forr our needs.

 

[GregSplett]

Mostly finished the fairing, but in looking at it I realized I should have rounded over the front corners it match the rack.

I used my jigsaw to cut the front tubes, crimped them, sealed them with silicone and bent them down out of the way until I can weld them. I may just leave them seeing as they aren't really needed for my application and serve no purpose. I have since sealed the bolt heads and painted them as well.

View attachment 161282

View attachment 161283

View attachment 161284

View attachment 161285

Pros:
CHEAP. Already had the wood and tools so I only needed the fasteners ($8) and a quart of paint ($9). I only used about 1/4 of the paint so I can use it on other projects.
Easily replace/repairable.
The fairing makes a world of difference in the noise level.


Cons:
Looks like painted wood. I should have sanded the fairing down to a nice 220 or so before painting. I didn't realize the grain would show up so much with brushing on the paint.
Doesn't look as "cool" as the aftermarket fairings.

When you painted it you raised the grain with the moisture in the paint.You get bored sand it smooth wipe it with a damp cloth let dry and sand smooth and paint.The wet rag raises the grain before the paint and keeps it down during painting.A couple of layers of good primer will take some of that away also.

 

[unabashedpraise]

When you painted it you raised the grain with the moisture in the paint.You get bored sand it smooth wipe it with a damp cloth let dry and sand smooth and paint.The wet rag raises the grain before the paint and keeps it down during painting.A couple of layers of good primer will take some of that away also.

Good idea. I would have done that if I had known. Sadly, my temporary fairing was not maintained properly with paint and it has started to peel. I have some plexiglass I'm planning on using, but required projects always seem to get in the way of stuff I'd rather be doing.

Sent from my XT1056 using Tapatalk

 

[GregSplett]

I am curios if it effects gas mileage at all.I have an old subaru I call the River rat.I use it steelhead fishing on the coast.Anyways it has a Thule to carry my kayak.The thing gets terrible gas mileage so any bit will help.I am regasketing the entire intake today hoping it will work in my favor.