Feather River Competition

[Bob]

Jan 29, 2024 23:20:21 GMT -5 @hefty said:

Do you think we're allowed to heat treat it?

I'm doing some research and it seems that flintknappers have heat treated it before to make it more colorful, I think it's also a technique to make the stone more hard/brittle for knapping. Reportedly, 12,000 year old native american points were suggested to be made from this jasper and those points were heat treated.

I live in Oklahoma and am surrounded by chert-laden areas including seeing many spalls that were heat treated by ancient peoples.  In some types it often causes beautiful lines which knappers call "fingerprints" and so the tumbled pieces are sometimes more pretty than otherwise.  I don't think you should do it unless you were to get permission as it would probably be considered tampering with the rock.  That's just my guess.

[Bob]

Jan 30, 2024 12:53:02 GMT -5 @hefty said:

Jan 30, 2024 11:14:10 GMT -5 Bob said:

I live in Oklahoma and am surrounded by chert-laden areas including seeing many spalls that were heat treated by ancient peoples.  In some types it often causes beautiful lines which knappers call "fingerprints" and so the tumbled pieces are sometimes more pretty than otherwise.  I don't think you should do it unless you were to get permission as it would probably be considered tampering with the rock.  That's just my guess.

Just sent an email asking.

I wonder if some or all heat treated stone wasn't intended to enhance the color or make it easier to knap, but to make it easier to mine. Using fire to fracture rock seems to be a common ancient tactic and where else would that be more applicable than a deposit of bedrock.

I'm not a knapper, but have friends that are really into it.  Usually they say that tempering makes it harder and more brittle which is good for forming projectile points and edges.  There are many chert quarries in Alibates Flint Quarries Natl Monument.  If you give them a call, they could tell you if fires were used to help break the material off the host layer.  I've been there and remember it being explained that fires were used but don't remember if for that purpose.

[Bob]

Is anyone else almost suspicious of this material?

After years of cruddy, porous, super challenging, time-consuming, weeks or months in rough grind material--after only 1 week in rough grind I'm seeing good rocks with few problems. Almost afraid to comment in case jinx it, but these look like I could get done in April or May instead of barely making the deadline each year.

[hplcman]

Feb 7, 2024 14:22:46 GMT -5 Bob said:

Is anyone else almost suspicious of this material?

After years of cruddy, porous, super challenging, time-consuming, weeks or months in rough grind material--after only 1 week in rough grind I'm seeing good rocks with few problems. Almost afraid to comment in case jinx it, but these look like I could get done in April or May instead of barely making the deadline each year.

I'm tumbling mine in a 3-pound barrel and am happy with how it's all shaping up.  They have been in there for over 3 weeks now and I just pulled 3 rocks last weekend for moving on to stage 2.  I think I'll collect these all together and run them through stage 2 as a monoculture (like the laker barrel being worked on by Starguy).  Initially that wasn't my plan, I was expecting to have to keep pushing these on though the later stages as soon as they were ready, but I think I'll have the time to do it this way.  

I'm expecting something to monkey wrench the process, like they don't polish well or are allergic to burnishing or something.

[perpetualneophyte]

Do you wait until the rocks are round or just until the grooves and cracks are smoothed? Also, I'm about to run out of my first batch of Polly Plastics kit. Do y'all have a recommendation for grit type and sources?

[hplcman]

Feb 8, 2024 15:48:22 GMT -5 perpetualneophyte said:

Do you wait until the rocks are round or just until the grooves and cracks are smoothed? Also, I'm about to run out of my first batch of Polly Plastics kit. Do y'all have a recommendation for grit type and sources?

I pull them out of stage 1 when they are smooth and defect free.  I usually dry them out and carefully inspect them, as the water can hide some small crack or imperfections.  Stage 2 removes some rock as well, so sometimes I'll move something along with very small imperfections.  
As for grit I (and most people on here I'm sure) strongly recommend buying your grit and polish from this place in South Dakota called The Rock Shed.  Go to their website and they sell kits that contain all 4 stages of grit for tumblers.  There will be 60/90 and 120/220 silicon carbide grit, and 500 and polish grits made of aluminum oxide.  Buy that kit and you'll be good to go!!!

[stefan]

SO far after 6 weeks I have 4 rocks ready to move on (flawless to the naked eye). I am very suspicious that the polish on these rocks is gonna be a real pain. It is just shaping too nicely. I do have 2 that are never going to go anywhere, but all the rest are just a couple weeks from being ready for 120/220

[cthomas]

I think I am at week 9? Just now moved the first bunch into stage 3. Still have a quite a bit in Stage 2 with some small imperfections, and a few with some egregious issues still holding on to stage 1. At this point I don't think the rocks in stage 1 will ever be contenders and will likely stay home with me. As the rocks wear down I'm finding a lot of them have small pin hole bubbles appearing, I think the final polish is going to be challenging.

[hplcman]

I am still tumbling 3 of the rocks at stage 1.  The rest are ready to move onto stage 2, once a 3-lb barrel is free (probably the week after next).  The ones that I pulled from stage 1 are >95% defect free, and will tumble a round or two in stage 2 to get them as close to perfect as they will be.  I'm concerned about polish with the rest of you, and would like to start that process as early as I can in order to address any polishing issues that come up.  

[rocknewb101]

I am so loving reading through and seeing your progress reports and predictions. I need to mark my calendar for December 2024 to start looking for this contest. What fun!

[roQhound]

I'm not really happy with any of mine. I've still got some larger ones in stage 1 and a bunch ready to move onto stage 2, but I see the same pinholes and looking very closely I can see small fractures that are going to be a problem. The ones I have showing dendrites are darker colored, better shaped and overall better than a lot of the lighter colored material. I've got holes and/or poor shapes with the lighter color. I think I'll have a few nice ones though (hopefully at least 5).

[Bob]

Mar 19, 2024 14:54:20 GMT -5 @hefty said:

I'm noticing pinholes and hidden fractures too. Nothing serious but minor flaws. I think technically they're only judging the polish and not the flawlessness of the rock. Any crack or hole scares me though just for the potential to trap and carry grit over that could contaminate the next stage. If I were confident I could remove the grit entirely, I don't think holes matter to judges. Not entirely sure though. And cracks I feel could go either way with judges, since it may have been inflicted during tumbling or been natural.

All you have to do is use the clear epoxy on the end of a toothpick or sewing pin and push a little in there and leave it just barely higher than the rock around it.  I do this to save rocks I really like from having pinholes at the end of polishing, so usually do it on some just before polish. 


But it would also work to keep in any contaminants like you say, and to do that you would not even need to fill up the pinhole to the surface.  FYI, super glue will not work.  I tried it hundreds of times before realizing it always failed.

[hplcman]

Mar 20, 2024 13:49:46 GMT -5 Bob said:

Mar 19, 2024 14:54:20 GMT -5 @hefty said:

I'm noticing pinholes and hidden fractures too. Nothing serious but minor flaws. I think technically they're only judging the polish and not the flawlessness of the rock. Any crack or hole scares me though just for the potential to trap and carry grit over that could contaminate the next stage. If I were confident I could remove the grit entirely, I don't think holes matter to judges. Not entirely sure though. And cracks I feel could go either way with judges, since it may have been inflicted during tumbling or been natural.

All you have to do is use the clear epoxy on the end of a toothpick or sewing pin and push a little in there and leave it just barely higher than the rock around it.  I do this to save rocks I really like from having pinholes at the end of polishing, so usually do it on some just before polish. 


But it would also work to keep in any contaminants like you say, and to do that you would not even need to fill up the pinhole to the surface.  FYI, super glue will not work.  I tried it hundreds of times before realizing it always failed.

I went back and looked at all the rocks I had set aside for stage 2 and ALL (except one) have these bogus cracks and pinholes in them.  They were still damp when I first assessed them and I must have missed those darn things.  I think I'll give all of them another round or two in stage 1 and see if anything is improving.  If not I'll try this epoxy trick, just to protect the later stages from trapped grit in those pinholes.

[Bob]

Mar 20, 2024 15:29:40 GMT -5 @hefty said:

Mar 20, 2024 13:49:46 GMT -5 Bob said:

All you have to do is use the clear epoxy on the end of a toothpick or sewing pin and push a little in there and leave it just barely higher than the rock around it.  I do this to save rocks I really like from having pinholes at the end of polishing, so usually do it on some just before polish. 


But it would also work to keep in any contaminants like you say, and to do that you would not even need to fill up the pinhole to the surface.  FYI, super glue will not work.  I tried it hundreds of times before realizing it always failed.

You're right, epoxy works well for that and you can barely notice it.

I don't think the judges would allow it though. Which is kind of a bummer cuz it would honestly be more impressive if a tumbler knows and can apply those more advanced techniques like epoxy stabilizing, epoxy filling, heat treating, etc. A lot more stones could be 'flawless' anyway.

I've also considered at least temporarily plugging some vugs with a material that could be dissolved away later. So the end product wouldn't be altered, but a druzy pocket or something could be preserved through the process without risking the rest of the stone.

A few years ago I asked the Contest about this.  I think the response was that it would not be considered a violation, but that it would be considered a waste of my effort because not needed.  I'm 90% sure, not 100% sure on my memory on that.  When I asked, I think I was asking about epoxy in cracks, not pinholes.  The idea being that doing that to a crack could help the crack not propagate and cause me to have to start all over if the rock broke apart in a late stage due to a crack.

[titaniumkid]

Mar 20, 2024 15:29:40 GMT -5 @hefty said:

Mar 20, 2024 13:49:46 GMT -5 Bob said:

All you have to do is use the clear epoxy on the end of a toothpick or sewing pin and push a little in there and leave it just barely higher than the rock around it.  I do this to save rocks I really like from having pinholes at the end of polishing, so usually do it on some just before polish. 


But it would also work to keep in any contaminants like you say, and to do that you would not even need to fill up the pinhole to the surface.  FYI, super glue will not work.  I tried it hundreds of times before realizing it always failed.

You're right, epoxy works well for that and you can barely notice it.

I don't think the judges would allow it though. Which is kind of a bummer cuz it would honestly be more impressive if a tumbler knows and can apply those more advanced techniques like epoxy stabilizing, epoxy filling, heat treating, etc. A lot more stones could be 'flawless' anyway.

I've also considered at least temporarily plugging some vugs with a material that could be dissolved away later. So the end product wouldn't be altered, but a druzy pocket or something could be preserved through the process without risking the rest of the stone.

Do you have recommendations for what could be used to fill vugs? I have a piece of rainforest jasper that will be a vector for grit contamination because a large, easy-to-clean vug is now essentially filled with concrete after the tumbler stopped in a power outage. I don't want to abandon it, so plugging the "concrete" might work.

[titaniumkid]

Mar 20, 2024 19:10:07 GMT -5 @hefty said:

Mar 20, 2024 17:52:11 GMT -5 titaniumkid said:

Do you have recommendations for what could be used to fill vugs? I have a piece of rainforest jasper that will be a vector for grit contamination because a large, easy-to-clean vug is now essentially filled with concrete after the tumbler stopped in a power outage. I don't want to abandon it, so plugging the "concrete" might work.

Have you tried an ultrasonic cleaner? Maybe boiling the stone first too might somehow get the concrete to rehydrate so the ultrasonic or a brush can work it free. Textile gun could probably blast it out.

If you want to seal over the mistake permanently tho I'd go with epoxy 330.

For a temporary plug, I haven't figured that out yet. I sometimes fill gaps with drywall mud during other lapidary projects. But drywall mud probably wouldn't last long enough in a tumbler.

Thank you for your insights. Maybe permanently filling it is the way to go if I can't get it clean. I was hoping there might be a temporary fill solution but tumbling could be too rough for such measures.

[perpetualneophyte]

I am using a NatGeo tumbler that rotates about twice as fast as a Lortone. After up to 60 days, I have just moved the full batch to stage 2. They have dropped just over 1 pound.

[cthomas]

Most of mine are still on Stage 2. A few I have promoted to stage 3. But all them have small little pin holes or even weird cracks. Not sure how I am going to get five good rocks out of these unless they are pea sized.

[dshanpnw]

cthomas, mine have the same pinholes and cracks. The rocks got pretty small. I'm glad mine aren't the only ones.

[wargrafix]

How much it costs? I couldn't open the site