# Whats your best technique for filing / smoothing fillet brazed welds.



## woody74 (Apr 6, 2004)

So I am filing away today trying to get my fillet brazed welds to look smooth and thinking this is taking ages and I wonder what tools, techniques other people use. Do people use power files or recommend me any certain sizes of file to make things easier? Any good techniques?

Thanks in advance


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## bluestarbikes (Mar 7, 2011)

Dave Kirk tutorial

The Framebuilders' Collective | Kirk ? Fillet Brazing


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## briderdt (Dec 14, 2012)

If you're good (like Eric Estland of Winter Cycles good), you pretty much don't need to.

Yeah, I'm nowhere near that good either.

I use a roto-file in a Dremel (wear ear plugs), and then go to files, then shop-roll 80-grit and my left thumb.

One of the things Dave Levy taught me (that didn't sink in until I was doing it on my own) is to not try to smooth it up until you "have a shape". Basically that means one continuous trench around the joint at the final (or close to it) depth, then start feathering it out.


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## adarn (Aug 11, 2009)

chainsaw files are the besssssssssst. Go get some. I used to do all kinds of weird stuff, but what seems to work best is a chainsaw file (I break the tips off so it's all cut) stroke it forward while twisting it axialy, and just go left, right, left, right... super slowly and werk yer way around. make sense? That and then 80 grit.

... but now I just TIG everything haha


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## Eric Malcolm (Dec 18, 2011)

Agree with the chainsaw files, they do work the best.

Even better is to improve your technique so you don't need to. This is a Work/time experience type thing, and when you notice that you are not filing as much as you did previously, you will know you're making progress. One improvement equals less work at the other end and is your best self teacher/personal achievement. 

Eric


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## woody74 (Apr 6, 2004)

Thanks guys, I totally agree that I need to improve my technique so there is less to do in the first place. Do you mean a chainsaw file like this 
https://www.chinachainsaw.com/photo/pl312599-chinese_stihl_chainsaw_chain_file_copy.jpg

I'll try the dremel and rota file as I have one of these kicking around.

Maybe off to buy a power file as well as I am sure it will be helpful for other stuff


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## adarn (Aug 11, 2009)

yep, those ones.


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## shirk (Mar 24, 2004)

Curious why the chainsaw file works better than a regular round file?

My first two frame have been a rush to get them done for a specific ride so filing the fillets smooth has not been a priority. 

My goal is to get my brazing to a respectable no file level or as I like to call it the "Garro Estland" standard.

Will need to build about 10,000 frame and melt 4 tones of brass to get there.


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## Eric Malcolm (Dec 18, 2011)

Shirk

Not sure why Chainsaw files work better, but they are made to file harder tooth steel material and brass is soft. It could have something to do with the file 'tooth' profile.
I know that if you err in your stroke while using one, they don't bite into the steel like an ordinary file will and yet they remove the brass better.

You don't have to make a lot of frames, you are more likely to have a eureka moment, then realise that you have got it right and then bliss.

Eric


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## adarn (Aug 11, 2009)

they just cut super nice and are a good size for the job. Also they're cheaper than regular round files.

I feel ya there. It doesn't take 10,000 frames nor 4 tons of brass like they'll tell you though (even if it took them that long). Just spend lots of time thinking about brazing when you're not brazing and don't let them convince you that it's that hard.


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## shirk (Mar 24, 2004)

Yes the line about 10,000 frames was meant to be sarcastic. 

I'll pick-up a couple of the chainsaw files for the next frame.

I've had a few small eureka moments in my brazing. Stiff need a few more for the dissimilar thickness items. Thick plate dropouts to thin tube needs some work.


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## Eric Malcolm (Dec 18, 2011)

Shirk

I think we understood the inference, great that you're on the up.

Some of the secret in getting the thicker material up to a tolerable heat is to (as much as possible), pre-heat the thicker piece, staying away from the braze-point for as long as you can, then feed the heat towards the braze area. That brings the thinner element up to heat real quick.

Eric


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## BungedUP (Aug 18, 2003)

With my limited filet shaping, I found that sculpting type rules apply: Start rough. Rough it out with as big of a file as you can get away with, such as a half round, and / or straight die grinder (not dremel, but air tool) with a cartridge roll / drum roll. Work the center down towards the edge, but don't work the edge itself. Don't try to use a small diameter file to shape with. If for example, with a small diameter file, you work the center down under the radius of the fillet that you want, you'll have to build it back up with brass (Almost like cutting the fillet in half). With a bigger radius file (such as a coarse half round), that is a lot harder to do. Use the rough tools until you just can't do it anymore, THEN switch to smaller tools. If you have an air compressor, buy yourself a straight die grinder and a couple of sizes of drums and rolls, and some cartridges. Don't faff about with a small file to do a lot of shaping. Doing it fast is good. Carving away at it slowly is, well, much harder.


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## jgerhardt (Aug 31, 2009)

Wow, I am surprised at this point no has mentioned using a dynafile.
That thing has DRASTICALLY reduced my fillet cleanup time.


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## BungedUP (Aug 18, 2003)

Well, sure - that's a good helper too, especially with a trampoline arm and a split (1/4") belt. I will say, they are better for final smoothing, whereas the cartridge roll is really good for helping to rough out the general shape - especially since you can use them to help establish a specific radius (if that's part of your game plan for the joint). But yes, if you can afford one (or multiple), Dynafiles are of course excellent.


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## seankanary (Feb 19, 2013)

I picked up the Horrible Freight dynafile and it works surprisingly well. I did however pick up better quality belts from the start.


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## jgerhardt (Aug 31, 2009)

I picked up my dynafile for relatively cheap as a factory refurbished model.  I use a 1/2" 60 grit belt that I have cut into three wavy strips for the rough work then I go in with small files to avoid any undercutting


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## afwalker (Apr 26, 2012)

+1 on good belts on the HF cheapo that works well after 10 bikes!
$32 for gosh's sake! 1/2" Bandfile Belt Sander 
Cubitron II is worth hunting down. 1/2" x 18 60 or 80 grit rocks
andy walker


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