Thread: Drum Sander Help

If resin is the problem, you will probably find the courser grits will clog even quicker. I never go under 120 on a drum sander as they run too fast for the courser grits and dust extraction on these machines is pretty inefficient. NGRW is not drum sander friendly and requires TLC.
A few tricks that may help: Keep your passes very shallow. Keep the feed speed up. Enter the timber on an angle into the sander so the board is not running perpendicular to the drum, this has a similar effect as an oscillating sander, using the full width of drum across the full width of board. Clean the abrasive after every pass (an old thong works well in conjunction with a spray bottle of kerosene.) The thong can be run across the drum while running, without the use of kero if the buildup in the grit is not resinous, but if it is, then kero will help break it down. You will need a final hand sand due to the semi diagonal scratches from the semi diagonal passes in the drum sander.

Originally Posted by rustynail

If resin is the problem, you will probably find the courser grits will clog even quicker. I never go under 120 on a drum sander as they run too fast for the courser grits and dust extraction on these machines is pretty inefficient. NGRW is not drum sander friendly and requires TLC.
A few tricks that may help:

Bugger, rustynail.

That is not what I wanted to hear. This NG Rosewood is a pretty timber but I'm beginning to wonder if it's more trouble than it's worth. It also makes a habit of forming bubbles and pinholes in the lacquer finish, especially on horizontal surfaces. It seems that I've defeated that problem with Solarez, but I still need to sand these veneers down to 2 mm.

The only good news is that dust extraction on my drum sander is wonderful.

Tell me about "wonderful." What sander, what dusty?

Originally Posted by rustynail

Tell me about "wonderful." What sander, what dusty?

It is a Performax 22-44 Pro (I'm told they are no longer made) with the dust port opened from 4" to 6". When I used this machine with a 1 HP mobile dusty dust collection was reasonably good. Now it is hooked up to a ClearVue 1800 the dust collection is magnificent.

What sort of thicknesser do you have? Neil erasmus made a jig for his felder combo where he can thickness veneers down to about 1.6mm without too much issue, might be another option to look at. His jig utilises his shop vac to draw a vacuum directly under the cutter head, keeping the thin piece being thicknessed stable and secure. In saying that, i haven't had issues drum sanding NGR with 80 grit, very light pass and going around half-speed on the variable speed dial on the supermax drum sander.

As mentioned, you need ALL the dust extraction

Originally Posted by hurcorh

What sort of thicknesser do you have? Neil erasmus made a jig for his felder combo where he can thickness veneers down to about 1.6mm without too much issue, might be another option to look at. His jig utilises his shop vac to draw a vacuum directly under the cutter head, keeping the thin piece being thicknessed stable and secure. In saying that, i haven't had issues drum sanding NGR with 80 grit, very light pass and going around half-speed on the variable speed dial on the supermax drum sander.

Time for a little experimentation. I'll try your approach with 80 grit paper. I'll also try angling the veneer so the resinuous strip moves across that drum rather than sitting in one place, as rustynail suggested.

Also, I might try running the veneers through the Woodman thicknesser on an MDF sled or similar. I use a sled when sanding these veneers, so I might as well try the thicknesser.

I use 60 grit on mine and its very good . 2 x 60 grit drums . One day Ill try 40 grit but haven't got around to it . I pump stuff through it . I don't get clogging problems . I would have problems getting the 60 grit marks out if it was a to be polished surface that was going through , but its rarely that. Its nearly always a glueing surface for me.

OK. I think the problem is solved, thanks to hurcorh.

I tried to use a sled to put the veneers through the thicknesser. However, that didn't work as the machine grabbed the veneer and pulled it forward leaving the sled behind.

So then I flipped the sled over and sat it on the lower platern of the thicknesser. In this orientation, the piece of veneer I glued onto the sled to prevent the machine from spitting the veneer back at the operator was holding the sled in place, effectively locking it into position. In the pic below you can just see the veneer glued onto the underside of the MDF sled, which prevents the sled being drawn into the machine. It just makes the platern about 16 mm thicker.

IMG20220831111954.jpg

The veneers are now 2.1 - 2.2 mm thick, leaving just enough to sand off before finishing.

Problem solved. Thanks for all the input!

Nice one. The benefit of Neils veneer thicknessing jig is your shop vacuum draws the veneer down directly under the cutterhead while it is passing through so you get a bit of suction keeping the thin board against the sled.

I think you will get a better result if you can get a small wide belt sander, yes the wide belt sander are in 3 phase 99% of the time, but you can do do one of the following:

1. change the main motor to a single phase and some electrical work.
or
2. phase converter.

I bought this small wide belt sander recently, barely used, not a runner when I got it, however it was just a few very simple pneumatic fix, all up and running after swapping out pneumatic parts and a couple of hours of work.

it looks small but the belt length is still 1500mm+

sander4.jpgsander1.jpg

Albert,

I'm sure you are right, so I found a second hand machine, saw the price and went into shock. I don't have the loot for a machine like that.

I think I'd spend money on a fair dinkum table saw first ... but for now will make do with the contractor saw built into an MDF cabinet.

Originally Posted by hurcorh

Nice one. The benefit of Neils veneer thicknessing jig is your shop vacuum draws the veneer down directly under the cutterhead while it is passing through so you get a bit of suction keeping the thin board against the sled.

Unfortunately that is of no use to me because my thicknesser won't let me adjust past a thickness of 4-5 mm. I could use the sled, and that allows me to cut down to infinitely thin, but I have already successfully planed the veneers without the vacuum jig using the 16 mm platern.

The rollers keep the workpiece pressed down pretty firmly, as well as feed the workpiece into the cutters. Given that I am not planing thinner than 2 mm, and that I have already done that, I don't think I'll investigate the jig right now. Thanks anyway. If I have a change of mind I'll contact neil for further detail.

Hi John

I used to live in PNG and used quite a lot of NG Rosewood - always back sawn to maximise that swirling grain - but never in veneer, so I cannot directly answer your questions. My stash ran out some 20 years ago, and when I learned Gunns prices I never renewed it - so my experience is 20 years out of date!

That swirling grain certainly looked great but it does mean that the grain direction may change several times in one piece of timber. This complicates things! Sanding often produced "hairy patches" - analagous to a suede finish - and these would show up as dull patches under any clear surface finish. Sanding was only ever partially effective.

My solution was to use a hand plane and card scraper (on solid wood). On your veneer, may I suggest that you experiment with a card scraper. I think a scraped surface is more alive than a sanded one.