Brush finishing a frame

[Mathias Scherer]

Hi list,

I'm looking for something to speed up the tedious task of brush finishing a
frame. After the welding I generally media blast the frames to a finish
similar to the one in the first picture (taken from Lynskey's finishing
options on their website)

http://www.lynskeyperformance.com/store/media/catalog/custom_options/finishe
s_standard.jpg

To achieve something like number 2 or 3 I then take various grades of
scotchbrite and finish by hand. The tubes are fairly easy (with the
exception of the parts where there are "braze ons"), but the joints and the
dropouts are a bit more difficult. What are you guys using to speed up the
process?

Cheers,

--
Mathias Scherer
Ludwig & Scherer GmbH
Wintringerstrasse 19
66271 Kleinblittersdorf

Geschäftsführer Mathias Scherer

[tim to]

Hi Mathias

To get a finish like 3 you can find one of these wire wheels and use a
hand drill. In tight corners i pull out scotch brite (cut into strips)
and have at it.

http://tooltray.com/images/products/LES41013307.jpg

The larger dia. wire wheels have longer (less stiff) bristles. I know
the image makes it look like it'd tear the heck out of the frame but
not so at all. It leaves a very nice even brushed finish over the
frame.

I also use this same wire wheel to 'clean up' my steel bikes before
pics - post finishing to even it all out. Looks more 'pro'. Helps on a
fillet to highlight flat spots as well by adding some uniformity to
the surface texture...

Tim

On Nov 18, 12:14 am, Mathias Scherer <Math...@Ludwigundscherer.com>
wrote:

> Hi list,
>
> I'm looking for something to speed up the tedious task of brush finishing a
> frame. After the welding I generally media blast the frames to a finish
> similar to the one in the first picture (taken from Lynskey's finishing
> options on their website)
>

> http://www.lynskeyperformance.com/store/media/catalog/custom_options/...

[Alistair Spence]

Matias,

I like the nylon stranded brushes that chuck up into a hand drill,
http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=3009910&PMAKA=990-2004

I get them in the three different grits (80, 120, 240) and use them on
things like stems or racks that are going to be electroplated.
Here's an example of a stem that I went over with those wheels,
working down through the grits, to hopefully give you an idea of
whether these give the look you're looking for,

http://www.flickr.com/photos/duncancycles/6244575031/in/photostream

Alistair Spence,
Seattle, WA.

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[Mark Bulgier]

Mathias Scherer wrote

>
> I'm looking for something to speed up the tedious task of brush
> finishing a frame.

Have you tried a hand-held belt sander with Scotchbrite belts? We used them to finish Ti frames, a couple places where I worked.

I don't know if this interests you, but this Scotchbrite belt sander method is safe enough and easy enough that you can hire unskilled workers to do that part of the job, if you're tired of it. There's very little chance they can harm the frame or themselves, unlike with wire wheels or abrasive blasting. Young bike mechanics are often willing to work for cheap or free, just to be able to say they work in a custom frame shop... They don't stick around long, but you've invested very little in their training, maybe 5 minutes? And there's one born every minute.

The best sander to get is the Dynafile by Dynabrade -- it'll change your life.

Are Dynafiles sold in Europe? They're expensive, but versatile, powerful and durable. They come up used on eBay now and then, if the new price is out of reach. They come in an electric motor version, but the air motor is much preferable if you have an air compressor. 3M also makes a high-quality and versatile contender (http://tinyurl.com/7f7hhcl), that I don't like quite as much but it is a bit cheaper.

Use the offset or curved contact arm (http://www.amazon.com/Dynabrade-11219-Diameter-Contact-Radiused/dp/B00065TOOM or http://tinyurl.com/6rxl5u7) It gives you an unsupported slack section of belt, where the belt can follow the curve of the tube. And where the belt goes over the wheel, it can get into joints and around braze-ons. You will definitely want a selection of contact arm shapes in addition to that one, so get the "Versatility Kit" if you buy a Dynafile, cheaper than buying all the bits separately.

Cheaper belt sanders are generally lacking in power and durability. They usually don't have different shaped contact arms, and also take shorter belts that wear out faster, so you spend more time changing belts. Generally speaking they don't sell spare parts or rebuild kits, so when they wear out you throw them away, unlike Dynabrade or 3M.

A cheap one could let you put one toe in the water though, to see if you might want to invest more.

Mark Bulgier
Seattle

[dave bohm]

The best sander to get is the Dynafile by Dynabrade -- it'll change your
life.

Are Dynafiles sold in Europe? They're expensive, but versatile, powerful
and durable. They come up used on eBay now and then, if the new price is
out of reach.

***********************************

There is a company in England called Seco Engineering that seems to make a
very nice one. Maybe superior in some ways to the fabled Dynabrade.

http://www.secoeng.co.uk/belt-grinders.php

Depending on exchange rates there prices are comparable or less than
Dynabrade.

Dave

http://www.users.zetnet.co.uk/seco/images/beltfibr.jpg

[Mathias Scherer]

Thank you guys for that. I think that's money well spent and I'll certainly
look into that. I'd want something where I can get the parts and the belts
in Europe for convenience, so I'll see what there is.

Cheers,

M.

--

[David Porter]

Re: Secoeng version. The balance of these and the later Dynafile with the
rotating drive and the short belts suck IMHO... find an old version electric
(good luck) or pneumatic. Also 3M has a new version they are offering that
is even lighter and ergonomic than the old DF.. also get the belt extender.
Longer belts last longer.. It too is pricey.
dave

fro...@porterscustom.com

Porter Customs 2909 Arno NE
Albuquerque, NM USA 87107
505-352-1378
1954 BN2 1959 AN5
Porter Custom Bicycles

cars:
www.britishcarforum.com/portercustoms.html
gallery:
http://picasaweb.google.com/porterscustombicycles/PorterCustomBicyclesStuff

GO HERE: http://porterbikes.com/ nice pictures-fun facts-my world

Cheers,

M.

Geschäftsführer Mathias Scherer

--

[Sean Chaney]

Mark, Mathias et all,

I JUST bought a Dynafile with the hope that it would make my pre-finishing process faster as well as to make it easy to touch up joints that get a little golden at the edges.  Let me say that it most definitely is NOT a faultless solution to post weld finishing.  Even the finest 3M non-woven ScotchBrite belts are too aggressive, I think mainly because of the stiffness of the backing.  The "superfine" leaves cut marks like 80 grit shop roll.  I've been unable to find anything that cust like the maroon or green hand pads.

I called 3M about it and they're making me some samples of a belt that they say is similar to 6000 grit paper.

I'd love to hear others experience with this, specifically about which belts were used.

Sean