Using sand as abrasive

[JB]

I've made an outdoor table top from hardwood which is furrowed and somewhat splintery (see attachment). I figure one way of smoothing the furrows well would be sandblasting, but I'd like to do the job in my workshop. Can anyone suggest a suitable abrasive material? Something like coarse sand would work well. It needs to be a loose material (ie not sandpaper) so I can work it into the furrows. It could be worked wet or dry (the wood can handle it) .

Any old-time methods or innovative suggestions would be appreciated.

[Trav]

Not that I can really tell what the whole table looks like, but I love that weathered look - especially when it gets smooth, and would be inclined to keep it!

I can't really help with the sandblasting idea. I know that you can get cheap compressors and sandblasting kits at supercheapauto - I ahve a compressor and it works fine. Not sure how the sandblasting would go. Not well, I suspect, with a cheap compressor.

good luck and let us know how it works out.

Trav

[RufflyRustic]

Hi JB

I've found wirebrushing works for me, but it was on much smaller pieces of weathered fence palings. it worked wet or dry, (I prefer dry though) kept the weathered look and took off all of the loose bits.

cheers
RufflyRustic

[JB]

Thanks for the suggestions. I do intend to keep the furrows, I just want to de-splinter them.
As far as supacheap sandblasters go, I don't think that would work as i imagine the object sandblasted has to be placed in a confined area, and the supacheap blasters are just a few cubic feet in size.

I've already wirebrushed ruffly, but I think the wood is strinybark and lots of slivery splinters are still evident. Like yourself I find wirebrusing is all that's needed on other hardwoods.

[Skew ChiDAMN!!]

Any panel-beaters out where you are? They may not have the facilites but should be able to point you in the right direction... and whoever they point you at would probably be both more informed as the appropriate particle size to use and delighted to do something besides blasting more metalwork.

[Andy Mac]

Hi JB,
Interesting problem you've got here...I think the plan to use sand has merit, but blasting it on can be a pain, and not always "natural" looking. Depending on the colour grit it can sometimes stain the timber too.
Maybe if you pile on some clean sand, wear big leather gloves and use lots of elbow grease you'll clean it up! Have you seen those stainless steel mesh gloves(gauntlets) used by slaughtermen? Fairly expensive but ocassionally they turn up in pawn shops, and I've heard of woodworkers using them to distress furniture.
My only other suggestion is way out, and you want to do this job at home ...but I'll tell you anyway!! Some years ago in FWW mag, some chap wanted a driftwood effect, so he placed boards at the outlet of a grain auger, where the wheat poured past all day. The result was highly successful, a soft polish with rounded edges. First, find you're wheat silo!
Cheers,

[echnidna]

Two totally different suggestions

a. Burn the splinters off with a blowtorch, then you should only need very light sanding.

b. The supercheap sandblasters will do the job but you only get a couple of minutes per blast run then you have to let the compressor pump up again. Takes a while but it will do the job. Do it over a tarp so you can recycle your grit.

[JB]

Andy
I reckon that grain auger idea would work brilliantly. I can imagine a very smooth finish would result similar to that achieived by natural erosion over a long period of time. If I ever move to a wheat growing area darned if I won't see if I can give it a try. In the meantime, here in Brisbane there is a concrete plant nearby..don't think it would be the same somehow...:eek:
I think I know what you mean about sandblasting...sometimes it looks a bit pockmarked?
I'll keep my eyes open for stainless steel mesh gloves (gauntlets). Be sad to see some poor knight tying his steed up outside a pawn shop before going in to try and flog off his gauntlets wouldn't it?!

Bob
Thanks for those tips. I might have a little play with the blowtorch tomorrow and see how it goes. I imagine it would certainly work to some extent, maybe a lot.
i didn't realize you could use sandblasters in an open space. You don't lose much/any of the sand?

Thanks fellahs.

[ubeaut]

Used to do a lot of this stuff many years ago. Used a flap sander with slashed abrasive in it. This followed all the contours and left a beautifully smooth surface that looked and felt amazing. Not sure where you would get it from now. I used to have a few Black & Decker Work Wheels which did the job. Try one of the bigger automotive trade stores for a flap sander that fits into a drill. They are available, you might just have to hunt for them a bit. Might also be available at Carba-Tec, Timbecon or one of the others.

Hope this is of some help.

Cheers - Neil

[spitnchips]

Hi JB
If you go for the sand blasting way, be careful with the dust, it isnt good for you (silicous) They use garnet to sandblast , but if you use beach sand or whatever clean sand you can get, take precautions.

[Richardwoodhead]

A technique I use successfully is to get a wire brush fitting (circular brush, long thread, narrow "cone" of wire) that fit's into an electric drill. You can then work the wire brush easily along the grooves. Or if you want to get really aggressive, they make circular wire brush fittings that attach to angle grinders.

Good luck with it. I think that weathered look will come up a treat.

Richard

[conwood]

Could be a hand job. I used hight pressure water to clean similar surface recently. Sand blasting will still leave you with lots of sanding. Perhaps a course cloth .. material may be better, like those scourer thingos for drills. a final light hand sand to finish the job.

If you don't want the furrows to be felt by hand you could then fill with a clear finish/epoxy product.

cheers,
conwood

[soundman]

One thig to watch with sand blasters is water in the air supply. They are high demand devices & unless you have some serious water seperation your filter reg won't manage to extract much.
This causes the gun to clog.
The finish achieved with a sand blaster coud be varied by the size & type of gritt. eg glass bead would give a less ragged resilt than one of the sharp sands.

Have you thaught of sand & a stiff broom or scrubbing brush.
cheers

[JB]

Sand and a scrub brush could do the trick; I'll try tomorrow. Thanks for the advice re sandblaster and water. Priced one in Supacheap today, about $50 for the sandblaster and $10 for a small bag odf sand which is cheap enough but haven't bought it yet.

Normally use a wire wheel in a drill for these jobs, as suggested by Richard, but problem with this table is wood just plain splintery; wire wheel just makes more splinters. A case of bad timber selection. Using old eucalyptus stockyard rails I've found the reds are MUCH better than the yellows, which I think are mainly stringybark. The reds aren't splintery at all.

I figure the only way I can make it usable is applying several coats of decking oil, enough to build up a coat over the fine splinters. would have preferred to leave this table dry, but not to be.

Thanks all for the helpful posts. There's been some great suggestions.

[Ausworkshop]

What about dragging it along behind your car while driving through sand at the beach? Never tried it but just a thought plus it sounds like fun.