what makes a quality abrasive for metal?

[mickthetree]

Hey all

I purchased some rolls of abrasive from the bay last year, which I adhered to my float glass (90cm long).

Thing is it doesnt seem to last very long.

Can anyone recommend a good quality abrasive in a roll that should last well on metal in this situation?

 

[Philly]

Wet'n'dry works well.
Philly

 

[mickthetree]

Hey Philly

For initial flattening I have used thisaluminium oxide abrasive dry in the past. I ordered 80grit off the same guy.

Would using it wet make it last longer? or just reduce the chance of overheating?

Only seems to last for 5 minutes of lapping before I have to replace it. Or is that just the way with sanding metal?

 

[studders]

Only seems to last for 5 minutes of lapping before I have to replace it. Or is that just the way with sanding metal?

I had the same problems with abrasives and metal. Until I dusted the moths from the wallet and bought some fairly expensive emery sheets from Axminster. The difference was very noticable, I could really feel the emery cutting and it did so for much longer.
By far the best though was the Veritas Powder Kit that I got, I think, from Rutlands. It is so fast it's almost unreal.

 

[Philly]

Mick
Yes, using a lubricant helps a lot. It removes the waste which keeps the abrasive clear so it cuts faster. Be wary of applying too much pressure - let the abrasive do the work for you.
Hope this helps,
Philly

 

[mickthetree]

Cheers Studders

Is thisthe veritas kit you mentioned? Did you get the lapping plate as well? or just use the powder on a flat surface? like float glass?

 

[mickthetree]

great stuff, cheers philly.

 

[studders]

That's the very stuff, goes an awful long way too as you only need a small amount.
Didn't get the plate as it seemed quite dear for the size plus, in the destructions that came with the kit they said any flat water/oil proof surface would do so, I just used an offcut of MFC.

 

[RobertMP]

Bought an awful lot of sanding discs in my time for linishing steel and stainless. Only the major branded stuff is worth buying. Norton, 3M or anything German . 'English abrasives' was not much cop but better than Indian or Chinese made.
I'd guess the same was true for wet and dry.

 

[Harbo]

You can "spice" things up a bit with Silicon Carbide grit (**** sells it) on wet & dry.
Using the grit on Acrylic sheeting also works - the grit, by embedding itself into the plastic, speeds up the process.

Rod

 

[studders]

Using the grit on Acrylic sheeting also works - the grit, by embedding itself into the plastic, speeds up the process.

Rod

I will give that a bash, it might also stop or slow down, the 'crushing' effect where I end up with finer and finer grit?

 

[Jake]

SiC doesn't break down anywhere near as fast as AlOx (most wet and dry is SiC)

 

[eoinsgaff]

I was lapping a few planes one time and the abrasive was getting clogged very quickly. I was working dry. The vacuum cleaner every 5 mins kept the sand paper refreshed.

 

[wizer]

what about the 3M Micro Finishing Film that Workshop Heaven stock?

 

[studders]

SiC doesn't break down anywhere near as fast as AlOx (most wet and dry is SiC)

Well it took a bit of searching to find out but the Veritas stuff is SiC apparently. It does take a while to wear it down though, seems to be the really heavy 90G that breaks down the quickest. Takes way longer to do so than the Wet and Dry I bought, which is from BlackSpur so probably not that surprising really.

 

[OPJ]

what about the 3M Micro Finishing Film that Workshop Heaven stock?

That's the same stuff I used last summer to flatten my plane soles. I glued several sheets to a length of MDF in order to give me a long enough run for my longest plane and it removed the high spots at an alarming rate! :shock: You do have to remember to un-clog it regularly - just tap the edge of the board on the edge of the bench and the 'dust' falls away.

No lubricant required. The backing is very thick compared to standard abrasive sheets so, I'm not sure whether clamping it would work, which is why I glued it on.

After that, I finished on a couple of finer grits of Wet and Dry (SiC) from CSM Abrasives. Don't go too high or you'll increase the risk of rust forming. I finished on 240g and it's been fine.

 

[mickthetree]

ah now I did get a sheet of that from Matthew and it was brilliant on a chisel back, but thought the edges might catch when laid end to end.

Mind you, sheet cut in half would still be wide enough, so only a couple would be required.

I think it retains its cutting ability long after aluminium oxide paper though.

 

[studders]

Another vote for the 3M stuff from WH. Though I didn't find it any quicker than the SiC Veritas 90grit it did 'seem' a more accurate way of flattening a planes bum.
I found on large areas it was difficult with the Powder to keep it evenly spread so assumed it was cutting more in one place than in others?