Thread: Radius Sanding blocks-

Originally Posted by kiwigeo

Stu,

Do you mean degrees or inches? My radius blocks are 9 1/2, 12 and 16" radius.

Cheers Martin

Yep, you're correct Martin.
You change the radius (inches)of the block by tilting your drill press bench to
differing degrees to the drill shaft.
I was thinking one thing and typing another.

Hi

I made a couple of blocks out of fibreglass.
Luckily I found some pipe/tube the right radiuses I was after and used these as moulds.
Another time I did The old sandpaper trick.

cheers

Originally Posted by boatchippy

Hi

I made a couple of blocks out of fibreglass.
Luckily I found some pipe/tube the right radiuses I was after and used these as moulds.
Another time I did The old sandpaper trick.

cheers

I used to be a panelbeater for many, many years before I did an apprenticeship as a carpenter.
Apart from crash and bash, we also moulded and produced fibreglass bodykits for cars too as a sideline business. Top fun.

I can see how well you could produce a radiussed shape that way with the correct radiussed tubing/profile or similar object.
That's a great method, Boatchippy.

cheers, Stu

Originally Posted by oz tradie

Here are a few options ;
Carbatec $139.00 Aud
Stew-mac $68.29 Aud + $18 postage

Even cheaper if you bundle an order at stewmac and purchase in bulk.

cheers, Stu

Jeebuz!!!!!!!

I just had a brain wave yesterday about how I could get a radius block set, It's been bugging me for ages.

I've got a very cheap and effective alternative sorted and have already made four of them (12") and It took me about 5 minutes and I used not power tools at all.

I took a peice of 300mm diameter pvc pipe and cut a length about 300mm long, then I cut it lengthways into about 100mm strips. I then used liquid nails to glue a basic handle onto the back of it. I now have four blocks of the same radius which I can glue different grades of paper too and not have to mess around with changing one block.

The pvc is around 10mm thick and does not bend or flex at such a short length.

Basically I can make any radius I want as long as it comes in a standard pipe size .

Cost me absolutely nothing because the pipe is free for me ( scrap from work) .

If anyone wants photo's Ill load them after easter.


Edit: Pvc pipe while close to the exact radius required is always slightly different, eg intead of being 300mm diameter exactly it is 295mm diameter approximately. same as 250mm pvc is not exactly 250mm internal diameter. However it is close enough for a hack like me. After all it is free isn't it?

Originally Posted by oz tradie

I used to be a panelbeater for many, many years before I did an apprenticeship as a carpenter.
Apart from crash and bash, we also moulded and produced fibreglass bodykits for cars too as a sideline business. Top fun.

I can see how well you could produce a radiussed shape that way with the correct radiussed tubing/profile or similar object.
That's a great method, Boatchippy.

cheers, Stu

Hi Stu
The hardest part is finding the right diameter tube. I made a 20" radius, unfortunately I just couldn't find a 16" which I also wanted to make, so I had to settle for 17" which was a gas tank at a service station.
The 20" was a concrete pipe. A little bit of prep work was needed to fill some pitt holes then just PVA and wax and start laying the glass. Used a straight edge and marked a line along the length of pipe to keep the radius in wind then glassed along that.

Reguarding the other method mentioned, I glued a length of 40 grit sandpaper to a tank. Using soft hoop pine, sanded the radius in, this took about 10 minutes of sanding as I pre scalloped a bit out of the blocks centre with a 4" grinder first. Both methods worked well and I was pleased with the final job.

How about pushing a board across a 10" table saw with the the blade tilted slightly. That should also work??

with an 80 tooth blade you would have a pretty fine finish right??

to get a 2 /14" width you wouldnt have much blade up at all

Sounds a bit scary but a bit simpler than fiddling with angles on the bench drill

Anyone tried this?