Geodigger Posted November 4, 2010 Share Posted November 4, 2010 Hello everyone, I have the Swamblaster MV-1 and seem to be going through the rubber pinch tubes like crazy (the one at the outlet end). At over $2.00 a pop this is getting expensive. I was told not to adjust the factory set regulator valve for the pinch valve assembly in the back ... but might be an option. Does anyone have any comments on this subject? Thanks in advance. Link to comment Share on other sites More sharing options...
pleecan Posted November 4, 2010 Share Posted November 4, 2010 (edited) On my CrystalMark ecoblaster had a pinch valve with the same problem.... I modified the pinch valve and replaced it with a air pistol inline so the air pistol acts like a air modulator and one can at will pulsed the air flow..... just a suggestion.... Also the fact that you are going through so many rubber tubing suggest that the rubber has aged and the plasticizers are gone and you should find another supplier with fresher rubber tubing.... PL Edited November 4, 2010 by pleecan Link to comment Share on other sites More sharing options...
MikeD Posted November 4, 2010 Share Posted November 4, 2010 On my CrystalMark ecoblaster had a pinch valve with the same problem.... I modified the pinch valve and replaced it with a air pistol inline so the air pistol acts like a air modulator and one can at will pulsed the air flow..... just a suggestion.... Also the fact that you are going through so many rubber tubing suggest that the rubber has aged and the plasticizers are gone and you should find another supplier with fresher rubber tubing.... PL Can you post a picture of that please? Thanks. Link to comment Share on other sites More sharing options...
pleecan Posted November 4, 2010 Share Posted November 4, 2010 Can you post a picture of that please? Thanks. A picture of the blow gun assembly that you can buy for a few dollars at the hardware store..... Configuration as follows: Air compressor..... dryer.... regulator.... (blowgun inline) .... intake air line to CrystalMark unit.... hose.... stylus Link to comment Share on other sites More sharing options...
tracer Posted November 4, 2010 Share Posted November 4, 2010 well, i'm thinking of the variables possibly involved in the problem and what could be done to lessen the likelihood of each being a problem. obviously, pleecan's comment about having good pinch tubes is important. if they're degraded at all, or if it's possible to get a "bad batch" that wasn't vulcanized perfectly or something (?), then that would be a non-starter. air pressure is a big variable that doesn't cost money to experiment with - maybe lower it a tad and see if you notice any difference. the quality and dryness of the media are factors. i wonder if you could get some good magnification and try to see how some of the failed tubes are failing? slice them lengthwise opposite from the failure point and examine it internally and externally to see if the failure is starting from the inside or outside. i'm brainstorming with myself, so laugh if you will. um, any part of the surfaces doing the pinching that could be polished a bit to help? anyway, the only other thing i can think of really is technique. obviously, there are only so many pinches that a tube is going to take, so the more you work the pedal, the sooner the tube's going to fail, all other things being equal. i guess everyone's kind of noticed that the first part of the blast seems the best at times, but if you've got good dry air and good dry media, then the stream might be better longer. dunno. has anyone tried cutting their own tubes to reduce the unit cost? this random stream of gibberish brought to you by tracer and his cat, who did not necessarily approve of this message, but who nonetheless hindered the typing of it to the extent felinely possible... Link to comment Share on other sites More sharing options...
jpc Posted November 5, 2010 Share Posted November 5, 2010 I have the same problem... and I just go with it. I find that if I do a solid day of sandblasting I'll wear out a pinch valve. I do this cuz, as tracer suggested, that first puff of powder is the best, so I am constantly up and down on the foor pedal. I am having trouble understanding the photo of the air blower. Is this your setup for actually controlling the sandblasting and just leave the pinch valveopen all the time? Cuz if so, that's pretty clever..., or is this going into the MV-1?, which confuses me. Link to comment Share on other sites More sharing options...
pleecan Posted November 5, 2010 Share Posted November 5, 2010 (edited) I have the same problem... and I just go with it. I find that if I do a solid day of sandblasting I'll wear out a pinch valve. I do this cuz, as tracer suggested, that first puff of powder is the best, so I am constantly up and down on the foor pedal. I am having trouble understanding the photo of the air blower. Is this your setup for actually controlling the sandblasting and just leave the pinch valveopen all the time? Cuz if so, that's pretty clever..., Yes that is correct.... air flow control with a blowgun valve capable of pulsed modulation. The original postion of the foot controlled pinch valve on the CrystalMark unit was located downstream just prior to the stylus assembly. I got rid of pinch valve completely and put a varible valve (blowgun inline) upstream on the air side because it is much easier to modulate a stream of pure air than an air /grit mixture..... works for me. PL Edited November 5, 2010 by pleecan Link to comment Share on other sites More sharing options...
crinus Posted November 5, 2010 Share Posted November 5, 2010 What kind of media are you using? Maybe that is just too harsh. I have no problem. I bought a packet of 50 when I bought the unit more than five years ago thinking I would be going through them. I may have used 10 of them and I do use the unit quite a bit. Maybe not much in the past six months but in general I use it a lot. crinus Link to comment Share on other sites More sharing options...
Geodigger Posted November 5, 2010 Author Share Posted November 5, 2010 Thank you everyone for your comments and suggestions! Tracer, I think I will explore the pressure issue first and then maybe dive deeper into this. Pleecan, has an interesting modification. The others are correct too ... probably using too much foot pedal action which I prefer when working on fine stuff like around genal spines, thoracic tips and furrows of trilobites. I have the "quick dump valve assembly" installed which is really handy for such tasks when you want to stop the abrasive airflow immediately. Thinking I will adjust the factory set pinch valve regulator first until the air just starts to flow out the nozzle end and then turn it back a tad ... this is why ... found this in the user's manual: "PINCH VALVE REGULATOR ADJUSTMENT The Pinch Valve Regulator adjustment is factory set to supply the correct air pressure to the pinch valve assemblies for normal operation. Any decrease of pressure may create a leak through the nozzle tip. Too much pressure will wear the pinch valve tube in a short period of time." Fossil preparation is tedious enough without worrying about equipment failure. Thanks again, Geodigger P.S. I will stay with the recommended 80 psi coming into the sandblasting unit itself ... like tracer said ... many variables to explore. Link to comment Share on other sites More sharing options...
jpc Posted November 6, 2010 Share Posted November 6, 2010 let us know sometime oin the future how your tests go... Link to comment Share on other sites More sharing options...
MikeD Posted November 6, 2010 Share Posted November 6, 2010 Yes that is correct.... air flow control with a blowgun valve capable of pulsed modulation. The original postion of the foot controlled pinch valve on the CrystalMark unit was located downstream just prior to the stylus assembly. I got rid of pinch valve completely and put a varible valve (blowgun inline) upstream on the air side because it is much easier to modulate a stream of pure air than an air /grit mixture..... works for me. PL That makes sense and looks like a great idea, but I am still having trouble visualizing how you activate the blow gun valve with your foot (assuming you are using your foot). I will also have to look into the air pressure issue. Link to comment Share on other sites More sharing options...
pleecan Posted November 6, 2010 Share Posted November 6, 2010 That makes sense and looks like a great idea, but I am still having trouble visualizing how you activate the blow gun valve with your foot (assuming you are using your foot). I will also have to look into the air pressure issue. Hi Mike: I no longer have a foot valve and the blow gun valve is the replacement. I find that I have better control on the air abrasion unit with the hand valve vs foot valve. PL Link to comment Share on other sites More sharing options...
MikeD Posted November 6, 2010 Share Posted November 6, 2010 Hi Mike: I no longer have a foot valve and the blow gun valve is the replacement. I find that I have better control on the air abrasion unit with the hand valve vs foot valve. PL OK. I usually have my specimen in one hand and the pencil in the other, so I need a third hand. I'm guessing you have something holding your fossil or your hands are more coordinated than mine. Link to comment Share on other sites More sharing options...
pleecan Posted November 6, 2010 Share Posted November 6, 2010 (edited) OK. I usually have my specimen in one hand and the pencil in the other, so I need a third hand. I'm guessing you have something holding your fossil or your hands are more coordinated than mine. Yes ... my fossil is stationary by it's own weight or if it is small...held in place with various clamps or vise... the other hand is holding the stylus. PL Edited November 6, 2010 by pleecan Link to comment Share on other sites More sharing options...
jpc Posted November 9, 2010 Share Posted November 9, 2010 OK, pleecan, so my deal is that I always use my left hand to hold the specimen and to roll it around to the correct angle compared to the stream of medium I am controling with my right hand. Just like Mike D does.... so could your system be set up with the blow gun being foot operated if you kind of set it into a wooden box of sorts so that it is steady and your foot would just step on it? I'm kinda liking this idea. Meanwhile, I would love to see a photo of your whole set-up. Link to comment Share on other sites More sharing options...
tracer Posted November 9, 2010 Share Posted November 9, 2010 of course you could do something like that, but the further you get from the pen with the valve, the weirder/less effective the initial flow should be, since you'd have a long column of compressible air in front of the valve. i'd make a bite valve that you can hold between your teeth and just chomp on that sucker when you want to get abrasive. whut? Link to comment Share on other sites More sharing options...
pleecan Posted November 9, 2010 Share Posted November 9, 2010 (edited) OK, pleecan, so my deal is that I always use my left hand to hold the specimen and to roll it around to the correct angle compared to the stream of medium I am controling with my right hand. Just like Mike D does.... so could your system be set up with the blow gun being foot operated if you kind of set it into a wooden box of sorts so that it is steady and your foot would just step on it? I'm kinda liking this idea. Meanwhile, I would love to see a photo of your whole set-up. Imagination and methodology is half the fun when trying to figure out whats best when it comes to micro abrasion techniques. I have also toyed with the idea of using the blow gun valve adapted into a sewing machine foot controller..... The proper way to do it is to use a solenoid valve to modulate air flow with a foot switch actuator...... My air abrasion setup is in pieces right now... I got 2 CrystalMark units, several air compressors and air dryers.... 2 sandbasting cabinets , a 3rd dental sandblasting unit still in its box been sitting there for over 1yr... just don't have the time to set up nor the space... last time I sandblasted was over 2yr ago... outdoors, in the back yard.... fortunately the majority of fossils that I find don't require micro abrasion..... I have invested into several ultrasonic bath units to remove clay matrix. Main goal right now is to collect fossils at various sites while I am physically able to and to prep later... when I retire and sitting in my rocking chair overlooking the lake.. watching the sail boats go by..... Edited November 9, 2010 by pleecan Link to comment Share on other sites More sharing options...
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