Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Troy Shaffer]

Even with my new machine I'm having problems not getting the scratches out. There not bad, like I need to go back a wheel. But can be seen under a loupe. I was having the same problem with my pixie. Thinking back now it seems like it started when I switched from no lube or water aid to using dawn soap.... what I used to use when wet sanding my airbrush and custom paint projects. I figured it's the same concept, but.... could that be the problem. I have cut lots of cabs with no issues and now I have been fighting this for about 6 months and it dawned  on me, could it be the dawn.
Thanks Troy

[Phishisgroovin]

i always have that problem also.
I end up using numerous different really really worn out 600 belts until i finally get satisfied enough that i polish and say i cant get it any better.
Alot of times trying too hard to get perfection ruins it.

[Troy Shaffer]

Yea my biggest problem is being a profectionist. I end up wasting to much time. Do you guys use a lubricant or just strait water.
Thanks Troy

[Phishisgroovin]

i only use straight water.

[lithicbeads]

Lubricant in cabbing is not good. Water is only used to keep the dust down and cool the stone. dry sanding works very well in some cases because the lack of lubricant ( water ) allows very fast sanding. The very fast aspect means you can use a rather fine belt with heat resistant stones like jade and you will get a fine finish that is also rather quick as the sanding is agressive. Many stones will " burn " and show scorch marks from dry sanding or just crack from the heat stress. As your sanding wheels wear you need less water because you have lost agressiveness and need to compensate by eliminating so of the water that causes a buffer or hydroplaning effect between the stone and sanding surface.

[bgast1]

Interesting point Frank. I started using a lot of water and also a few drops of mineral oil onto my lap discs. For me I think that it is working better than less water. But it is still too early for me to tell. But now that I have convinced myself to wear a mask, I may attempt dry or almost dry sanding on my expando unit. But I am curious and do not know the answer to this. Won't dry sanding on diamond wheels and discs cause them to wear out really fast? I will look forward to this answer before proceeding with dry grinding on my 80 grit diamond wheel.

I just thought of this, I have an Ameritool machine, basically the same as the all-you-need machine. They have resin discs. One thing that I have noticed is that when they get dry the cab begins to drag and it cuts a groove on the surface of these discs. I think you need at least some water drip to prevent this.

Scratches. Well my friend are you beginning to become impatient and wanting to move from one disc or wheel to the next? I have had that problem for a long time as well. The point that I want to make is that I keep telling myself that this is not a speed contest. It is art, and art sometimes takes a very long time to get it done and right. I keep telling myself that it's done when it's done. So what if it takes 2 hours on one disc or wheel. I will not sacrifice quality for anything. I know that I will have to make adjustments in the way that I price things because if I included a rate for how much time it actually takes my product would be astronomical. So in the end, I just go by like I just said. I will not move from one wheel or disc until I am satisfied that the scratches are out. Sometimes though spending more time polishing will help a lot. I will sometimes go through the entire process to identify problems and then go back and rework if necessary.

[lithicbeads]

Dry sanding with diamond softback wheels works best when the wheels are worn out for normal use . Grits 400 and up are the ones used. When I was production cutting on a machine with a sic expando on one side and interchangeable diamonds wheels , hard and soft , on the other It was extremely impractical to go back a grit to get scratches out so I regularly used a hard 600 grit diamond wheels to make sure all the scratches were out before I went to the 100 grit diamond softback wheel. A pretty fool proof method.

[Troy Shaffer]

That makes a lot of sense. Hydroplaneing for sure. Don't feel that drag like I used to. Not a mater of impatience, I examine the stone after each sanding step. And get high gloss stones with micro scratches. It's gotta be the soap lube. I thought you need it cuz diamond pacific sends water aid out with there machines. Never used it but then got scared I'd wear my wheels faster and when I started using a fresh water system tried to save money with the dawn instead. Back to fresh water only and we'll see if that fixes the problem. I was actually cutting faster without the soap.
Thanks

[lithicbeads]

Brand new softback wheels of the finer grits are well known to need a short break in period ( sanding a few agate cabs ) especially nova wheels . Novas are great wheels because they have lots of diamond and hard wearing matrix. While that  causes scratches initially it makes for a very long lasting wheel. Production cutters often prefer the eastwind softback wheels in the coarser grits as they have a faster cutting rate than the Nova wheels with the harder matrix. Time is money so replacing wheels more ofetn is less important than the operators efficiency.

[PhilNM]

Lose the dawn except for cleaning between wheels. Not good as a coolant. It actually increases cohesion on your stone. Go back to what you used before.

[Sandsave]

Troy what type of equipment do you use? Ifs it a geyser type? I used to have a diamond pacific and battled this all the time. Had to really keep it clean, basically your recycling water and it's hard to keep clean as go you from wheel to wheel. Changed to a cab king and life's but a dream!

[bgast1]

I would like to jump in here with a question. I have an Expando unit. I have both diamond and SiC belts. Is cutting dry faster for these enough to warrant skipping the water? Also I have a piece of denim to spread out the water flow over the belts. Is that possibly a source of contamination if the water flow is pretty good?

Also cutting dry will of course wear out belts faster. Approximately how much faster? Fast enough that you are constantly replacing the belts or not significantly enough for it to be a factor.

[lithicbeads]

Cutting dry seems to wear the belts less. The risk to you and your family is great however. Dry sanding should be saved for a separate shop away from home and family. Sanding is very quick dry but it damages most agates and quartz based stones. It is a great high production tool  and is especially good for jade but should not be seen as a general money saving technique as the clean up time needed and the risk are too great. Swabbing down the surfaces in your shop after dry sanding to make it safe again is too time consuming to be practical and it takes years to develop the skills to sand the dome of a quartz based stone withoput damaging a fair percentage of them. A much better solution is to invest in a metal 600 grit wheel to get most scratches out before you start sanding.

[Itsandbits]

Sandsave; you could have saved yourself the cost of a new machine by just converting the existing one to a gravity irrigation :)

[bgast1]

hanks Frank. The information in that last post was exactly what I needed to know. So wet it is. The next thing that I will need to do is invest in a socket or wrenches the correct size to interchange the wheels when necessary. I have an 80 grit hard diamond wheel on the right side and an expando wheel on the left. I .am looking for the ideal setup. I own a second expando wheel. Perhaps we should take this to another thread.