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how do you cut a nice radius onto a sharp edge
smart51 - 28/12/08 at 04:47 PM

I'm making all my bodywork with sharp edges that I will then cut a 3mm radius on before painting. I've either sanded the filler flat or have been generous with the gelcoat in the corners to there is enough material to cut in to. How do you cut a nice constant radius onto an edge? I could use sand paper by hand but the radius would change all along the edge.


JoelP - 28/12/08 at 04:55 PM

maybe an electric sander to help you get it even?

i mean the vibrating random orbit sort...

[Edited on 28/12/08 by JoelP]


blakep82 - 28/12/08 at 05:22 PM

perhaps (never tried myself) sand the corner you want into a block of wood, and use that as a sanding block?


mr henderson - 28/12/08 at 05:34 PM

If you can get a hand held 1/4" router on to it, you can use a bearing guider 3mm radius roundover bit.

Alternatively just sand it by hand and use your fingers to feel for any discontinuities

John


Fred W B - 28/12/08 at 05:44 PM

I make steel templates/checking plates with the radius I want - drill a hole the diameter you want, and cut it open, file it square.

Pu a guide coat of paint on and sand with a block, checking with the template, which you can also use as a scraper to put the edge on. Soon you get the hang of it, and can work mainly by "eye", just checking occasionally. You will see a straight line appear at the start of the radius in the guide coat you are sanding off.

I prefer to do this work by hand, one slip with a power tool and you ruin the edge/radius

Cheers

Fred W D


[Edited on 28/12/08 by Fred W B]


Fred W B - 28/12/08 at 06:00 PM

I went and took a couple pics to illustrate. Hope this helps

Cheers

Fred W B


temp 1
temp 1



temp 2
temp 2


John Bonnett - 28/12/08 at 06:14 PM

A method I cribbed from Craig Seymour's very informative website http://craigsphoenix.se7ens.net/.

Drill a 6mm hole in a piece of stainless steel sheet and slice it across its diameter. You then have the correct radius. You can use this tool as a scraper to put the radius on the sharp edge.

hth

John


YQUSTA - 28/12/08 at 06:17 PM

if you have a router you could put a cut in it so the sand paper fits that would give the same as above but would be as long as you like.


chrsgrain - 28/12/08 at 07:11 PM

I would have gone for the router - but it sounds like Fred has got it sorted - by the way Fred - where is the latest update on your bodywork - we all like to see your work...

Chris


Fred W B - 28/12/08 at 07:33 PM

quote:

Fred - where is the latest update on your bodywork -



Thanks Chris - Look down a few posts in this section? I did an update on the 22nd

Cheers

Fred W B