Granat Abrasives
- Thread starter MTRANGER
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Granat has a zinc stearate. For that reason, we're not sure how it may react with various types of finishes. Tim Morris, a FOG member, happened to visit the office a week or so ago and offered to test it out with different spray finishes. I haven't heard back from him but hope to get his feedback soon about how it performed.
If you're using paint, it's not an issue.
If you're using paint, it's not an issue.
Brice Burrell
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JJ Wavra said:
JJ, get with it man, you just repeated MT's question. [poke] [big grin] [big grin]
Tim Morris
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OK guys just to keep with full disclosure I was provided this product by Festool USA. The initial intent is to try it with several finishes to see if the abrasive causes any contamination such as fish eye. I spray a lot of different finishes in my shop typically to match something I am dealing with on one of my remodels. I have not had a chance to work with this other than to stain some sanded samples tonight. I intend to give these sample different finish coats 1) vinyl sanding sealer with pre-catalyzed lacquer, 2) catalyzed conversion varnish and 3) water borne finish (which I am still not a fan of). [unsure] I have been told that the product has already been tested by another contractor with latex paints and there are no problems.
I did get a chance to work some bare wood as this is what I was most interested in. I was given a small package or 125mm 120 grit, so for comparison sake I will compare it to 120 grit Rubin, as Rubin is what I typically use on bare wood. I used mt ETS 125 for the test machine. I would also like to try it against Brilliant but didn't have any on hand. I first ran a piece of red oak through my wide drum sander to mock a glue up panel as I would make for a raised panel door. I intentionally used a rougher grit than I would normally to "scratch it up". I first noticed that the backer material is much more flexible, on Granat, the than the Rubin. I think this will aid the disk in following a profile when used with one of the softer backer pads. I sanded 1/2 of the piece with each paper. I think the Granat completed the same task in about 2/3 the time of the Rubin. I know most of the work being shown on this forum would be sanded much finer that 120 but I continued as if this was my finish grit just for comparison sake. I then inspected the piece with an inspection light, as I would after sanding anything coming out of the drum sander. All lineal scratches appeared to be removed. I then took the piece in the finish room and stained them with a dark lacquer compatible stain to magnify the orbital swirling left by the paper. There was of course orbital scratches left by both papers. I thought the Granat looked to be just lightly less, but not significantly different. I am thrilled to think that I could reduce my sanding time by 1/3 on large project like panels for a kitchen for example. I don't think any more or less grits are going to be needed to take a given species or project to "finish sanded" and ready to finish. I guess I didn't think about it until I started typing this but this could be significant time if it saved 1/3 on each successive grit.
I haven't had any time to try the paper removing old finish to test clogging, nor have I sanded enough to test the longevity of the abrasive against any of the other papers available.
All in all I am impressed with the new paper so far I think if it preforms over the long haul as well as it did on this small test there will be a savings in labor and sanding materials. [big grin]
THANKS again to Shane and Festool USA.
I did get a chance to work some bare wood as this is what I was most interested in. I was given a small package or 125mm 120 grit, so for comparison sake I will compare it to 120 grit Rubin, as Rubin is what I typically use on bare wood. I used mt ETS 125 for the test machine. I would also like to try it against Brilliant but didn't have any on hand. I first ran a piece of red oak through my wide drum sander to mock a glue up panel as I would make for a raised panel door. I intentionally used a rougher grit than I would normally to "scratch it up". I first noticed that the backer material is much more flexible, on Granat, the than the Rubin. I think this will aid the disk in following a profile when used with one of the softer backer pads. I sanded 1/2 of the piece with each paper. I think the Granat completed the same task in about 2/3 the time of the Rubin. I know most of the work being shown on this forum would be sanded much finer that 120 but I continued as if this was my finish grit just for comparison sake. I then inspected the piece with an inspection light, as I would after sanding anything coming out of the drum sander. All lineal scratches appeared to be removed. I then took the piece in the finish room and stained them with a dark lacquer compatible stain to magnify the orbital swirling left by the paper. There was of course orbital scratches left by both papers. I thought the Granat looked to be just lightly less, but not significantly different. I am thrilled to think that I could reduce my sanding time by 1/3 on large project like panels for a kitchen for example. I don't think any more or less grits are going to be needed to take a given species or project to "finish sanded" and ready to finish. I guess I didn't think about it until I started typing this but this could be significant time if it saved 1/3 on each successive grit.
I haven't had any time to try the paper removing old finish to test clogging, nor have I sanded enough to test the longevity of the abrasive against any of the other papers available.
All in all I am impressed with the new paper so far I think if it preforms over the long haul as well as it did on this small test there will be a savings in labor and sanding materials. [big grin]
THANKS again to Shane and Festool USA.
Brice Burrell
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Thanks Tim, please keep up update as you learn more.
Tim Morris
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John I totally agree with your "industry" statement. That is why I made sure that was on the list of finishes to work with. I know there have been several discussions on here about water borne. I will try to work with that material tonight and report back.
i have granat 40, 150, 240 and use rubin 80 and sometimes 150 in between. (i only start on 40 when there is a coat of any sort that has to be removed first).
there is a slight difference between rubin and granat 150 -> the finish is a slight amount smoother to the touch with granat second. (i used rubin first and granat second and vice versa on two halves of a board of pine). granat does not clog. it just doesnt. i used it to strip really tough outdoor paint and such and it holds up really well against clogging. rubin seems to be more tough against mechanical damage since it is a lot more rugged and has thicker backing paper. it clogs really fast on the other hand (it is not made for sanding finishes, just for bare wood). anyways, my conclusion is: granat is the best allrounder. you can take a coated piece of wood all the way from 40 to 400 grit with granat and it will be perfect. its just that rubin might be cheaper if you dont need the non-clogging abilities of the granat. i guess it comes down to mechanical damage resistance vs. clogging resistance (rubin vs. granat).
there is a slight difference between rubin and granat 150 -> the finish is a slight amount smoother to the touch with granat second. (i used rubin first and granat second and vice versa on two halves of a board of pine). granat does not clog. it just doesnt. i used it to strip really tough outdoor paint and such and it holds up really well against clogging. rubin seems to be more tough against mechanical damage since it is a lot more rugged and has thicker backing paper. it clogs really fast on the other hand (it is not made for sanding finishes, just for bare wood). anyways, my conclusion is: granat is the best allrounder. you can take a coated piece of wood all the way from 40 to 400 grit with granat and it will be perfect. its just that rubin might be cheaper if you dont need the non-clogging abilities of the granat. i guess it comes down to mechanical damage resistance vs. clogging resistance (rubin vs. granat).
Tim Morris
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Here's a clogging testament I just tried. I have a table top in the shop I started to make a mock up for a customer about 4 months ago. The idea was to make a simple, inexpensive harvest type table that he could sell in his re-sale store. He wanted something that if a customer came in and wanted a special size we could have pricing and lead time worked out and just take the order. The only way I could keep the price where he wanted it was to use cheap #2 ponderosa pine for the material, meaning big box pine boards. I glued up a 30x65 pine top, clamped it and let it dry. When it was ready I took it out of the clamps grabbed the Rotex and some 120 grit Rubin and went on the attack. About 2 1/2 square feet, 12 disks and 30 minutes later I decided that I would have more in sand paper than material. I called him and explained the situation and asked if he would be willing to raise the selling price a bit, to offset the labor and paper. He felt that he could not charge any more in the location where his store is or the clientele he was after. So I bowed out. That top started taunting me this afternoon. Short story I loaded the old Rotex up with Granat, 4 disks and 15 minutes later and it's ready to go to the next grit. It did most certainly clog the paper, but at the rate of about 1 to 20 with Rubin [eek]. So far this stuff is amazing.
Second project. I have sanded a piece of baltic birch ply and applied water based finish. It had been on for about 45 minutes when I came up from the shop just now. So far, keep you fingers crossed, there was no sign of orange peel or pitting. I'll sand lightly later and apply another coat and report back.
On a side note Shane I'd like to place an order for another box of each grit from 80 through 320 Thanks. [cool]
Second project. I have sanded a piece of baltic birch ply and applied water based finish. It had been on for about 45 minutes when I came up from the shop just now. So far, keep you fingers crossed, there was no sign of orange peel or pitting. I'll sand lightly later and apply another coat and report back.
On a side note Shane I'd like to place an order for another box of each grit from 80 through 320 Thanks. [cool]
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Ok, so here's the "official" word on Granat, direct from Germany.
There is no problem using Granat before a finish is applied. This includes latex-based paints as well as any other finish, including clear polyurethane and other water-based finishes.
There was a time when stearate coatings used a wax which caused issues with some finishes, particularly water based finishes. Modern Festool stearates don't contain any wax.
We don't recommend using Granat in place of Rubin because it has a thinner backing which will not stand up to sanding on corners and edges as well as the more robust backing on Rubin. Also, Granat creates a more aggressive scratch pattern than Rubin on bare wood.
I hope that clears up the questions about Granat. My apologies that I didn't know the answers sooner.
There is no problem using Granat before a finish is applied. This includes latex-based paints as well as any other finish, including clear polyurethane and other water-based finishes.
There was a time when stearate coatings used a wax which caused issues with some finishes, particularly water based finishes. Modern Festool stearates don't contain any wax.
We don't recommend using Granat in place of Rubin because it has a thinner backing which will not stand up to sanding on corners and edges as well as the more robust backing on Rubin. Also, Granat creates a more aggressive scratch pattern than Rubin on bare wood.
I hope that clears up the questions about Granat. My apologies that I didn't know the answers sooner.
Tim Morris
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Thanks Shane. I concur. I have had a chance now to work with this product with several finishes and stains with zero problems, including water based finish. [big grin]
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Tim Morris said:
Tim, thanks a bunch for taking the time and effort to check that out and give independent confirmation of the results. I think it's safe to say that various finishes will definitely not be an issue with Granat.
Brice Burrell
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Yeah, a big thanks to Shane and Tim. [thumbs up]
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