Power Sanding Pads

[wizer]

sounds familiar, the pads kept flying off and then when I looked the velcro had melted. I think the pad might have flew off a couple of times and the Velcro against wood may have created enough heat to burn it, even tho it was for a couple of seconds a time.

 

[tekno.mage]

Has anyone used Abranet with this system. Maybe that's the problem? i.e the mesh transfers the heat directly to the pad?

I do sometimes. You need a very gentle touch and I only use the coarser grits. You do risk damaging the velcro on the pads by abrasion (it prokes through the holes in the abramet) and possibly heat. The velcro also clogs up with sanding dust.

I mainly use Hegner's Rhynored sandpaper with sanding arbours.

On the subject of arbour types, I've used Skilton. Hegner & "no-name" off ebay (50mm and smaller, mostly) The Skilton ones are the most expensive and come with hex shanks. I've not found they last any longer than the Hegner ones which are much cheaper. Don't bother with "no-name" ones off ebay - any I've tried last about 5 minutes.

The main failure I find with them is that the velcro eventually comes off (constantly pulling the disks on and off weakens the glue join) but you can stick it back on. On my oldest Hegner arbour (velcro re-stuck a couple of times) the velcro is now no longer holding the disks as well - I don't think this is heat damage as all velcro fasteners go like that eventually. The hooks wear out.

tekno.mage

 

[TobyB]

Tom - I have done exactly what you did with the Abranet - maybe pushed a bit hard, maybe it was the teeth protruding through - eitherway ... abrasive gone and seconds later velcro hooks melted/worn away ...

 

[CHJ]

Tom, IMO as has been inferred above, if your disc contact is firm enough to generate enough heat to melt adhesive or damage the velcro then you need to use it with a much gentler hand.

(Don't take offence, I do it wrong regularly)

If it is cutting correctly then the lightest of touches should work, if it is not removing stock as quickly as you would like then go for a coarser grit or change the disc.
I know the discs can eat pennies rather quickly but they have a very limited effective cutting life with some woods, not uncommon to have to resort to a 'Use Once and throw' policy.

A good indication of how lightly you should apply abrasive is to hold a piece of Abranet against the work and see how quickly the dust burns your fingers, if it's too hot to hold it stands a good chance of damaging the wood.

 

[wizer]

Cheers Chas. I didn't think I was pressing hard, I knew not to from hand sanding. The lathe was near it's lowest speed and the drill was on low too.

 

[duncanh]

I think it was one of the pros demoing at our club that said the best way to prolong the life of sanding discs was to use a different arbor for each grit - that way you're not continually removing and attaching abrasive to the velcro.

Of course, he was probably sponsored by an arbor manufacturer Most of us won't be able to afford to, but I'm sure it would help.

Duncan

 

[wizer]

I'm going to look into making the arbours. Anyone suggest a suitable pad material?

 

[CHJ]

Tom, have you got a decent (ball bearings not Bushes) friction driven disc holder.
These impart far less load on the discs, can't remember the last time I had to resort to using a sanding disc in the hand drill.

The very nature of having to get the approach angle correct to get a good drive encorages better cutting action and life IMO.

 

[DaveL]

I'm going to look into making the arbours. Anyone suggest a suitable pad material?

Have a look at old mouse mats? Some of the older ones have quite a nice rubber mat as the base, two or three layers stuck together might work? :-k

 

[tekno.mage]

I'm going to look into making the arbours. Anyone suggest a suitable pad material?

I've made a couple of sanding arbours using offcuts of Armaflex foam which is a closed cell nitrile foam used in the HVAC industry to line trunking for insulation and sound reduction. It will certainly take the punishment of being a sanding arbour and is reasonably heat resistant. It is usually supplied in large sheets or 25mm or 18mm thick (or as tubes for pipe insulation) but if you know anyone in the HVAC industry you may be able to acquire some offcuts - I first discovered offcuts of the stuff in a skip outside an HVAC installers warehouse, and when I enquired inside was told to take as much of the stuff in the skip as I wanted for free. I have since bought a few full sheets to insulate the floor of my van (which doubles as camping accomodation) - makes marvellous sleeping mats for tents too.

tekno.mage

 

[wizer]

Tom, have you got a decent (ball bearings not Bushes) friction driven disc holder.

Chas, do you mean a hand held tool. Like the RS Sandmaster? Yes I do, it looks very similar to the one in your original thread. AFAIK it's a bearing system. I actually picked up a interface pad for it at S&B (AST) but they only had the soft ones so I haven't yet used it. Was going to save it for when I had some tight curved to sand. I can try this, indeed I can make my own pad for it.

Thanks Dave and Mage for the material recommendation. I'm more likely to find old mouse mats than the armaflex. But I'll keep an eye out. The PC's here at work are delivered with a foam type material that might work. It's similar to polystyrene but not flakey.

I just found this article which has a lot of useful info.

 

[CHJ]

The reason I say ball bearings Tom, is that if they just have plain bushes like the Sorby for instance, then the grit/dust gets into the bush/shaft interface and grinds away both bush and shaft, also it takes more pressure to get the thing to drive because of increased friction unless you oil it occasionally.

This then has the added benefit of improving the shaft grinding action and coats your work and everything else in a generous black stippling unless you hold a rag around the bearing.

 

[wizer]

understood Chas. Will check it tonight. Thanks

 

[wizer]

I wonder what glue would be ideal for gluing the velcro onto the pad?

Oh and where would I get 3" velcro?

 

[jpt]

John Lewis sell self adhesive velcro in 1", 2" & 3" about £2 to £3 a metre.

The best glue I have found to use for this is copydex it bonds well and stays pliable so less risk of the bond letting go.

john

 

[jpt]

Forgot to add craft foam is very good for making sanding pads and is cheap.

For self powered sanders the best makes, in my opinion are Vicmark and by the look of it the new one sold by Hegner as they have sealed bearings that dont need oiling.

john