3m wheels

[samiam]

Some areas are too tight for the wheel. They take a lot of sanding/filing, starting with coarse grades and working up to a scotch brite pad. It's a tedious process that will remind you how awesome the scotch brite wheel is.

[Bryan Cotton]

Typically I would run the edge of something like a hockey stick along the side of the wheel. If it was rough, like from a bandsaw cut, I would use the vixen file first. Much like Mike L says, you only do what you can on the wheel.

[kmacht]

I never used the scorchbrite wheel. Instead I got a cheap 1"x30" sander from harbor freight and bought scotchbrite belts from mcmaster carr. They were only a few bucks each. The belts are flexible enough that they get into tight spaces and abrasive enough that the metal doesn't need any pre work to take out all the ridges. If you search the old posts here you will probably find the belt part numbers.

Keith
#554

[NWade]

The video has not aged all that well, but I made a YouTube video about the HF belt sander and woven/scotchbrite belts many years ago. It’s still online here:
https://youtu.be/yWXSbFNwKUA

The McMaster-Carr website carries the belts, and there’s a link to them in the video description.

Enjoy!

—Noel

[RCfly46]

Ditto on the HF belt sander. It's become my favorite finishing tool on my YX build. I think it's much more versatile than a Scotch-Brite wheel on a bench grinder, but if I actually need the wheel there's one in the EAA shop a couple hundred yards from my hangar. I mostly use the blue belt for finishing work. The maroon belt is good for taking out marks from courser cuts. And if I really need to remove material I'll occasionally use the sanding belt.

I'm almost done with my fuselage and I've only gone through two blue belts and one maroon belt. Wings are up next.

Joe
YX181

[Zack]

For future readers, I recommend draw filing. I used the scotch brite wheel a bunch, but I found it difficult to get into certain areas and the end was never square because I used a wheel (duh). I am working on a 2011 kit and need to make (and remake) much of the angle myself, so I've had a lot of experience with both methods. I've found draw filing to be quicker than using the wheel and it leaves a better surface. You'll need a vise. It's a very simple technique. Here is a good tutorial: https://www.wonkeedonkeetools.co.uk/fil ... aw-filing/

I use the band-saw first, then get close with a 50 grit belt sanders. I skip this step for factory provided parts like the original poster described. I then use a Nicholson 8" second cut file to square up the edges and take out the cut marks and finish with a 8" or 6" smooth file. Files are affordable and last much longer than the 3M products. I've found Harry J. Epstein Co. has a good selection of new-old-stock made in USA files.

[WesRagle]

Hi Guys,

The video has not aged all that well, but I made a YouTube video about the HF belt sander and woven/scotchbrite belts many years ago. It’s still online here:
https://youtu.be/yWXSbFNwKUA

The McMaster-Carr website carries the belts, and there’s a link to them in the video description.

Enjoy!

—Noel

HI Guys,

I'm with Noel and Keith 100% on this. The 1" belt sander with a "scotch bright" belt is the way to go.

Here is a pic of the most used power tool in my shop:



The tool was suggested by Tony S. years ago and Tony never steered me wrong.

Here is a widget I just made:



The only things touched by the scotch bright wheel are the slight clearances on the angle next to the flange. All the rest was cleaned up with the scotch bright belt.

The backed part of the belt is used for edge finishing and to radius corners. You can work all the way around a piece quickly. The non backed portion of the belt can get into some of the more difficult places.

The disk sander and guide can be used to quickly square up cuts or, for instance, grind off a cut hinge flush with the last hoop.

You can see the scotch bright wheel in the background of the first pic. Had the same one forever and it is badly worn but ..., It is only used for "grinding" aluminum like I had to do to the nuts on the oops fittings to clear the fuel tank.

Come to think of it, scotch bright wheel and clearance/grinding always show up together. The rest is a job for the belt.

All the Best,

Wes

[Rynoth]

what type of sanding needs to be done? is there a video showing the proper way to do the sanding? is it the same as sanding wood?

I think that any method that gets to a smooth finish (no visual marks and definitely no fingernail-catching marks) is a good method, provided that it doesn't involve overheating the material (if it's too hot to touch you're getting close to overheating it and reducing its strength/temper.) I think it's mostly a matter of getting the rough/cut part of the material removed down to a point where a scotch brite polish will take care of the imperfections you cannot visually see, whether that's through filing, sanding, or scotch brite.

A better question might be if there are any methods/materials that are NOT good, i.e. certain types of abrasive materials that cause issues with 6061-T6 aluminum. For this I don't know the answer.

In any case, I would consider scotch brite as a final touch on any aluminum part whether it's from a pad, a wheel or a belt, just to go beyond the visual imperfection stage to really smooth.

[Zack]

Wes, I don't see it as an either-or but an all of the above, depending on the situation. The 1" scotch brite belt sander gives you a right angle and a flat surface, which addresses a lot of the limitations with the wheel. For small angle and plate I could match the finish with draw filing but not the speed. I would find the 1" belt a limitation for long parts, thick plate, and interior surfaces (such as the waiex y-tail doubler and y-fittings). Draw filing works great for these. It's much faster than "typical" filing where you push inline with the file tang and gives a much better finish. Draw filing requires single or double cut files, vixen files are not ideal. A 8" second cut* file is the right mix of material removal and surface finish. I'll finish up with a smooth file and then with a scotch brite pad.

(*) Second cut describes the coarseness of the file and is somewhere in the middle.

[WesRagle]

Hi Zack,

Of course you're right. The more techniques you have on hand the better. There are always situations when one technique trumps another. I was just trying to point out that I think the scotch bright belt is greatly under appreciated. Once you get used to having one you will find it is the tool of choice in a lot of situations.

Wes