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benupton
16th July 2011, 06:21 PM
Hi,
This is my review of Astra dot sand paper. It's kind of short. More to come.
The Wood Nook: Astra Double & Single Dot sanding disks (http://thewoodnook.blogspot.com/2011/07/astra-double-single-dot-sanding-disks.html)
Regards Ben

cookie48
16th July 2011, 09:34 PM
Is it really as good as it appears? Plus what is the costing for 50mm??

benupton
16th July 2011, 09:54 PM
It is actually very good, from what I think. Better for use on a rotary sander than regular sandpaper.

HSS
16th July 2011, 11:06 PM
I understand how it could work well but unfortunately I think it's a bit expensive. You can get standard velcro backed pads for less than half that if you buy in bulk. But, depending on how effective and durable they are they might be worth it. I'll think about it.

Did they last longer than conventional pads or reduce the time spent sanding?

hughie
17th July 2011, 12:51 AM
I use astra dot exclusively and if you buy in bulk its not expensive.

http://www.woodworkforums.com/f8/astra-dot-sandpaper-metre-127481/

bellyup
17th July 2011, 09:27 AM
Hi Hughie,
What method do you use to cut the rolls into discs?
Thanks,
Bruce.

hughie
17th July 2011, 02:41 PM
[What method do you use to cut the rolls into discs?




Bruce,

I trim them by hand, if you leave a slight excess on the disc this helps to prevent premature wear to the hook pad on the sander. Otherwise a large wad punch made from an old hole saw

rsser
19th July 2011, 05:56 PM
A forum member, TTIT?, ground the teeth off a hole saw IIRC and cut a bunch at a time.

I use 2" diameter discs, and have put an edge on the inside of a length of 2" muffler pipe for use as punch. Supporting with end grain blocks rather than side grain works better; or MDF.

bellyup
19th July 2011, 06:06 PM
Thanks Ern,
I'll have to go and look for a Subaru WRX and knock off the chrome exhaust for a 3" disc cutter :)

rsser
19th July 2011, 06:34 PM
Ain't battery powered angle grinders a wonder? :D

But I suspect the hole saw is more efficient all round.

NeilS
20th July 2011, 01:27 PM
Did they last longer than conventional pads or reduce the time spent sanding?

My tests (see here (http://www.woodworkforums.com/f8/took-few-sanding-abrasives-test-run-132081/)) comparing a few abrasives showed that Astra Dot was faster than the cheaper abrasives but not as fast as Vince's Cera~Max and no faster than Vince's Blue Flex or Norton's Dry Ice. Its durability was superior to most abrasives other than Cera~Max in the lower grits, which was the outstanding performer for me on durability.

I was a bit limited on my Astra Dot supplies when I was undertaking the tests, but based on what I had this was my summary on Astra Dot:

"If speed is not such a factor for someone then Astra Dot is worthy of consideration, especially if you cut the disks yourself from rolls. Using a full set of Atra Single and Double Dot disks may also give a different result. Its non-clogging performance in wet and oily woods is a feature that may be an additional attraction for some turners."




... a large wad punch made from an old hole saw

+1
.

hughie
20th July 2011, 02:01 PM
http://www.woodworkforums.com/f8/hole-punch-sanding-discs-66063/#post675592

Wizened of Oz
21st July 2011, 06:45 PM
Is it necessary to cut them round?
I just cut my abrasives square (about 60mm sq. for the 50mm sander).
Seems to me these work even better than the rounds.

rsser
21st July 2011, 08:24 PM
Even edging the perimeter say into the corner of a bowl foot?

NeilS
22nd July 2011, 10:53 AM
Is it necessary to cut them round?
I just cut my abrasives square (about 60mm sq. for the 50mm sander).
Seems to me these work even better than the rounds.

When I'm working close up to details (like beads) I use perfectly round ones and take care to place them concentrically on the mandrel so I don't get any run-out. This avoids obliterating the crispness of the detail. I find sanding next to the foot ring (viz Ern's comment) or other fine details the most challenging part of sanding.

Likewise, I don't use square inside bowls. The overhangs flex and create sharp creases that dig in and create deeper scratches.

Square is fine on the outside of bowls if there are no detail areas.
.

robo hippy
27th July 2011, 03:14 AM
Interesting. From my experiments with the Astra Dot, I found them to be very poor performers. They didn't cut well, in part due to all the open spaces and there not being as much abrasive on the discs. For durability, they seemed to go dull very quickly.

My preference is for the Blue discs from Vince. I compared them to the Dry Ice discs once by sanding out a 4 bowl cored set of Oregon Myrtle wood bowls (California Bay Laurel, and I have no idea why it is called Myrtle). The wear was almost identical. As was typical for the Blue discs, by the time I got to the 4th bowl, the discs were almost done, and I could have changed them out, but for as small as the last bowls were, there was no lost time. Considering the Dry Ice discs cost about 2 1/2 times as much as the Blue discs, I won't change.

I tried some of Vince's pink discs as well. I really like them. I would say that the coarser discs tend to outlast the blue discs by a bit, but not much, and the higher grits seemed to wear out/get dull more quickly.

How you sand is as important as the abrasives. I am a fan of slow speeds on the bowl, and on the drill. Since my bowls are all warped, I have to have slow lathe speeds (10 to 15 rpm I had my 3 phase converter re programmed on my Robust). I also run my drills at very slow speeds, at most half speed in the 600 rpm range, and often slower than that. The abrasives seem to cut better/more effectively at those speeds. Added benefit is almost no heat build up. I keep the eraser stick handy to clean the discs frequently. I have tried the high speed sanding, and it didn't work for me. I also soak in LDD (liquid dishwashing detergent) which makes a huge difference in how the bowls sand out: less clogging, and less tendency to glaze over/burn/heat up.

Typical for me is numerous bowls from one set of discs. A couple of large bowls, or 5 or more smaller bowls. I have found with the Blue and Pink discs that they can feel dull to the finger rub test when compared to a fresh disc, but when you put them on the wood, there is still a lot of dust coming off.

Some one needs to invent an articulated arm set up for holding the sanding drills!

robo hippy

rsser
27th July 2011, 11:15 AM
TTIT has crafted a flex shaft drive for his.

Air powered would be good with an angled head but you need a big compressor.

Milwaukee make (made?) an angle head electric drill so access may be a little easier but IIRC it's not that light (and we can't buy them downunder anyway).

...

And Dry Ice are meant to be run fast.

robo hippy
27th July 2011, 03:35 PM
I have one air powered drill, and it kept the compressor running non stop. Took way more electricity to run the compressor than to run the angle drills.

There are a number of knock off drills that are almost clones to the Sioux/Milwaukee drills that sell for $80 to $30. Since they are made in China, I would think you could find some there. Also called 'close quarters drills". Two types, a right angle drill, and an angle drill. Right angle one is more difficult to get down inside a larger bowl.

robo hippy

rsser
27th July 2011, 04:10 PM
Yeah, I did find a knock-off angled-head from a US sanding gear supplier but the voltage diff was still a prob (240 is std) here, and the speed control was a continuous paddle so still too much effort for those with failing hands.

Now use a right-angle Makita drill and yes, access can be a prob. but somehow having the weight align with the forearm works better for me than trad electric drills which can get 'whippy' if you're in a hurry.

hughie
27th July 2011, 05:25 PM
I have a knock off chinese drill that I bought at a ridicously low price a few years ago. Its still going :o absolutely amazing, to that I fit all manner of sanding accessories mostly home made.

rsser
27th July 2011, 05:41 PM
Sigh, Hughie, you know the line ...

'Didn't happen without ... '

govarney
1st August 2011, 06:23 PM
Gidday,

You guys are talking about bulk purchase and cutting your own discs, but I am of the understanding that you can no longer purchase the astra papers in bulk.

If you can, I'm interested to know where ? Thx

Sturdee
1st August 2011, 10:07 PM
If you can, I'm interested to know where ? Thx

I organised a group buy for a few forum members late last year from the Sandpaperman (http://www.thesandpaperman.com.au/) as a result of Hughie's thread on sandpaper. (http://www.woodworkforums.com/f8/astra-dot-sandpaper-metre-127481/)


Peter.

govarney
5th August 2011, 10:10 AM
Thank you Peter

hughie
5th August 2011, 02:48 PM
]Sigh, Hughie, you know the line ...
Didn't happen without


:U yeah yeah I know, but its buried in some box in the shed, tried to find it the other day. When I do I will start another thread just on XU1 power tools and their uses :U