I wanted to bump this thread and ask G-man if the silicon carbide worked? After using a true bar I wasn't satisfied with my bases and I am getting nothing done using my normal sanding belts.
Is silicon carbide the trick?
Any experience using it dry as I don't have a wet setup?
Sanding belts for UHMW
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
Hi powdercow,
Actually, I've been using my belt sander with silicon carbide belts in dry mode quite a bit lately and it works reasonably well. I use a 60 grit belt initially which takes down the base pretty quickly... well, quickly as compared to aluminum oxide belts. Then I switch to 80 grit, then 120. The 60 and 80 leave a fair amount of hairy texture. Lastly, I often do a hand scrape with a nice sharp cabinet scraper.
The weak point of silicon carbide belts is that sanding metal (like a ski edge) will decrease their cutting efficiency really fast. So, they work well in base high situations, but they don't work for bases that are concave... another plus for routing edge clearance in the core. My bases usually turn out pretty flat, but on one pair recently, I got my edge grooves just a little too deep, and the bases ended up a bit high. So, I'll be more careful to get the groove just the right depth from now on.
I still think that wet sanding works better than dry, but I ran out of room in the heated part of the shop this winter and some of the machines had to go to the non-heated section. For awhile, I was having too many hassles with the water freezing on the sander, so I reverted to dry sanding.
I use a 6" x 48" belt. It takes a pretty good sized motor to drive it if I'm working on a wide base.
G-man
Actually, I've been using my belt sander with silicon carbide belts in dry mode quite a bit lately and it works reasonably well. I use a 60 grit belt initially which takes down the base pretty quickly... well, quickly as compared to aluminum oxide belts. Then I switch to 80 grit, then 120. The 60 and 80 leave a fair amount of hairy texture. Lastly, I often do a hand scrape with a nice sharp cabinet scraper.
The weak point of silicon carbide belts is that sanding metal (like a ski edge) will decrease their cutting efficiency really fast. So, they work well in base high situations, but they don't work for bases that are concave... another plus for routing edge clearance in the core. My bases usually turn out pretty flat, but on one pair recently, I got my edge grooves just a little too deep, and the bases ended up a bit high. So, I'll be more careful to get the groove just the right depth from now on.
I still think that wet sanding works better than dry, but I ran out of room in the heated part of the shop this winter and some of the machines had to go to the non-heated section. For awhile, I was having too many hassles with the water freezing on the sander, so I reverted to dry sanding.
I use a 6" x 48" belt. It takes a pretty good sized motor to drive it if I'm working on a wide base.
G-man
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Car_ve_diem
- Posts: 11
- Joined: Wed Nov 29, 2006 8:38 am
a router?
am i missing something? or are you talking about trying to take off enough extra material so that you can run your router? I would try a dremel of some sort possibly?!?!?! not very precise, but if your going to use a router it probably wouldn't matter much as long as you don't eat up your metal edge...
sorry if this is useless info...
am i missing something? or are you talking about trying to take off enough extra material so that you can run your router? I would try a dremel of some sort possibly?!?!?! not very precise, but if your going to use a router it probably wouldn't matter much as long as you don't eat up your metal edge...
sorry if this is useless info...
Great info as always G-man.
You are very right aluminum oxide does zilch on bases but I have found worked fairly well on my edges. I supposed I will run silicon carbide for base high situations and aluminum for edge high. Or just use my files to lower the edges.
Also good information on the finer grits. I waxed my skis after sanding them with 50 grit and although they looked good they were slow for sure. For me base prep and tuning stuff is in a way turning out to be the hardest part. I am excited for the time when I get better at it.
You are very right aluminum oxide does zilch on bases but I have found worked fairly well on my edges. I supposed I will run silicon carbide for base high situations and aluminum for edge high. Or just use my files to lower the edges.
Also good information on the finer grits. I waxed my skis after sanding them with 50 grit and although they looked good they were slow for sure. For me base prep and tuning stuff is in a way turning out to be the hardest part. I am excited for the time when I get better at it.
- Ben
Carv_ve_diem,
I guess I wasn't very clear regarding the use of the router. In using the router, I was referring to the process where some builders route a little groove in the bottom side of the core (prior to pressing) to allow for the thickness of the edge 'teeth' in the lay-up. Pressing without the groove seems to result in a slightly concave base. Too deep of a groove, I now realize, can result in a convex base. When I take the time to get the groove depth the exact thickness as the edge teeth, the ski comes out of the mold with a very flat base. I often don't do anything but 'wax and go'.
G-man
I guess I wasn't very clear regarding the use of the router. In using the router, I was referring to the process where some builders route a little groove in the bottom side of the core (prior to pressing) to allow for the thickness of the edge 'teeth' in the lay-up. Pressing without the groove seems to result in a slightly concave base. Too deep of a groove, I now realize, can result in a convex base. When I take the time to get the groove depth the exact thickness as the edge teeth, the ski comes out of the mold with a very flat base. I often don't do anything but 'wax and go'.
G-man
My skis got their third base prep in as many weeks of life.
The silicon carbide worked much better than aluminum. I ran them dry (borrowed belt sander) so it still takes some time and patience but the end result is good.
I would also like to highly recomend ensuring that your bases are flat to any ski builder. Wavy bases totally changed how my skis performed and it would be sad to prematurely right-off a shape for such a minor reason.
The silicon carbide worked much better than aluminum. I ran them dry (borrowed belt sander) so it still takes some time and patience but the end result is good.
I would also like to highly recomend ensuring that your bases are flat to any ski builder. Wavy bases totally changed how my skis performed and it would be sad to prematurely right-off a shape for such a minor reason.
- Ben