minerken
Cave Dweller
Member since August 2013
Posts: 466
|
Post by minerken on Feb 19, 2018 14:27:45 GMT -5
It has recently come to my attention that there are problems with some materials releasing after polishing especially when using super glue. Personally I use acetone as the release option, one of members brought up the fact that this is all good and well unless you are dealing with a treated stone such as much of the turquoise is these days and then another member related problems with discoloration and when using some softer material that the cabs would break or in one case left a large divet where the glue was. I personally haven't had these problems but have to admit that I don't usually work with anything very soft and have not tried to fill a crack or pit or to my knowledge any treated stones, haven't done any turquoise. I kind of have a personal investment in this due to the dop sticks I make and offer for sale. I don't want to misrepresent the product in anyway. So off to YOUTUBE undoubtedly there are probably some or maybe many aware of this individuals videos and they are in fact probably fairly basic for you veterans but I think they have a lot of merit for beginners and may even have a few tips for the others. So here goes
|
|
Tommy
Administrator
Member since January 2013
Posts: 12,104
|
Post by Tommy on Feb 20, 2018 12:24:52 GMT -5
Thanks for the post minerken! I've been meaning to make a post about this but since Friday I've been buried in a fence building project that still has quite a ways to go. All - I have recently become a recipient of one of Ken's dopping handles and heads and I can truly say that I was extremely impressed with the design and craftsmanship. I've been free-handing for a while but it's been leading to a loss of skin because my wheels are fairly tight together on my home brewed cabbing machine. Lately I've been playing with the idea of dopping again and Ken's device as rockjunquie has attested to is well-designed and it feels as good in the hand as anything I've ever tried. Personally I think he should be asking quite a bit more for them with the amount of time he spends on them but that's another subject. I especially like that he made mine of a certain shaft size and showed me how I could go down to my local hardware store and purchase materials for more heads if needed.  On the subject of releasing - whether it's Ken's heads, or nails, or aluminum rod, dowels, or ... I've always just had a hard time with it and don't feel like I've ever found the "perfect" combination. Sadly, to me, dopping equates with breaking stones trying to get them off and I just can't get past it. I've tried acetone several times in the past and it just doesn't get it done for me given the wide range of materials that I'm working with at any given time. In this example picture this is a medium hardness orbicular rhyolite I call "wildflowers" - I work with it a lot. I soaked it in acetone overnight and when putting some pressure on it the dop broke loose and took a deep divot of material with it. Ken's theory is probably correct that the glue soaked into the material.  The "best" combination I've found to date for not breaking stones was poplar wood dowel with a healthy dollop of JB Weld - with removal being done with a mini hacksaw blade held very close to the stone. In that method the glue is just such a pain to mix and apply and keep the sticks secure long enough for the glue to set. Based on the mild success I had with that system, I'm toying with the idea of continuing to use these metal heads but finding a soft plastic sacrificial layer to add between the metal and stone that allows me the option of the mini-hacksaw blade if they don't fall off from immersion in very hot tap water, or from being in the freezer overnight.
|
|
|
Post by rockjunquie on Feb 20, 2018 12:32:08 GMT -5
Tommy - I have had a lot of success getting the stone really hot of the 50 and 100k polishing wheels and then just popping them off. It's not to hot to crack most stones, but the super glue starts to get soft. I think Pat posted the temp range for CA in another post. I'll see if I can find it. I was only not able to get one stone off and then I used acetone. eta can,t find it now. I'll look later- cabbing now.
|
|
Tommy
Administrator
Member since January 2013
Posts: 12,104
|
Post by Tommy on Feb 20, 2018 12:35:55 GMT -5
Tommy- I have had a lot of success getting the stone really hot of the 50 and 100k polishing wheels and then just popping them off. It's not to hot to crack most stones, but the super glue starts to get soft. I think Pat posted the temp range for CA in another post. I'll see if I can find it. I was only not able to get one stone off and then I used acetone. I read your post about it before and I've been trying a variation of it using *very* hot tap water and maybe one in four came off like that for me. Our water heater is set to much hotter than I would feel safe getting a stone on the wheels without burn marks. I also stuck the wildflowers stone in the freezer for two days but it didn't budge so into the acetone it went.
|
|
|
Post by Pat on Feb 20, 2018 13:22:37 GMT -5
rockjunquieThis is what you saw in Barclay's intarsia thread: From Satellite City website (maker of Hot Stuff) How do Satellite City instant glues hold up to heat? Tested by exposure for 5000 hours, our instant glues retain: 100% initial bond strength at 140 F (60 C) 75% at 176 F (80 C) 25% at 212 F (100 C). Our CA glue will melt at 330 F and start to soften before that. That's the facts on heat. Didn't see anything on cold. In your experience, how cold is too cold? It rarely hits freezing here. Read more: forum.rocktumblinghobby.com/thread/82178/first-intarsia#ixzz57fqLidpD
|
|
|
Post by Pat on Feb 20, 2018 13:33:46 GMT -5
I haven't read this entire thread, but on the rare occasions I use a dop, I use Locktite gel. Never a problem. Fast and easy. To remove the cab from the dop, I lay it on my soldering brick, heat the dop (a nail) with mini-butane torch, and in about a minute or two, the cab slides off the nail head.
|
|
minerken
Cave Dweller
Member since August 2013
Posts: 466
|
Post by minerken on Feb 20, 2018 13:50:04 GMT -5
One of the reasons That I decided to post the two vids in particular was the dopping of wello opal using the wood glue and nail polish protection coating. I had not heard of this technique before, unfortunately(IMHO this would probably be limited to using a wooden dop). A light application of acetone should weaken the nail polish and expose the water soluble wood glue and make it easy to loosen and remove, I have never tried this but I may. When I hear about perplexing problems like this my OCness kicks in and I have to  in some cases, so I'm off to research more about glues and double sided tape. Tommy and @rockjunkie thanks for your input on the subject, I hope that this will prompt others who may have favorite techniques to join in and expand on the subject and perhaps some of you adventurous souls may endevor to do a vid tutorial showing them feel free to attach here if you would like to keep the conversation going.
|
|
Tommy
Administrator
Member since January 2013
Posts: 12,104
|
Post by Tommy on Feb 20, 2018 15:59:34 GMT -5
Tested by exposure for 5000 hours, our instant glues retain: 100% initial bond strength at 140 F (60 C) 75% at 176 F (80 C) 25% at 212 F (100 C). That's really interesting information - I just now tested my hotest water and it's around 141 F at which point this says I'm still 100% bonded. I'll try a test with boiling water and see what happens.
|
|
|
Post by Pat on Feb 20, 2018 16:22:51 GMT -5
TommyI emailed them to ask what the coldest temperature which would not degrade. No response yet. Curious. Rarely gets below freezing here.
|
|
|
Post by aDave on Feb 20, 2018 16:37:03 GMT -5
Tested by exposure for 5000 hours, our instant glues retain: 100% initial bond strength at 140 F (60 C) 75% at 176 F (80 C) 25% at 212 F (100 C). That's really interesting information - I just now tested my hotest water and it's around 141 F at which point this says I'm still 100% bonded. I'll try a test with boiling water and see what happens. I'm only asking, as I don't know, but I find this stuff interesting. I'm assuming that the cab itself will need to reach 212 F before the glue bond is weakened to 25% of initial strength. Will the cabs survive that sort of heating in boiling water without fracturing? Seems like kind of a risky venture, depending on any imperfections in the cab. Then again, I really don't know, and that's why I asked. 
|
|
minerken
Cave Dweller
Member since August 2013
Posts: 466
|
Post by minerken on Feb 20, 2018 17:23:32 GMT -5
aDave that is a very good question I have wondered that myself All that I know for sure is that there is a whole world out there dealing with bonding Items together and just because it says super glue etc. it doesn't mean that it works in every instance or for intended purposes. Loctite one of the leaders in bonding agents has many formulas depending on the environment that it's intended for. rockjunquie seems to have come up with the glue with the perfect formula to release when she want's it too and so has Pat for her technique. @ Tommy has introduced another variable material type and how the glue reacts to it. There are so many variables that I really hadn't paid much attention to I am rapidly coming to the conclusion that there is really no universal answer other than use what works when it works and something else if it doesn't what a pain in the a$$ this may be. For certain I wouldn't want to use Barclay glue and boiling water or a torch to release opal but in the Wello Opal vid it worked with the glue he used
|
|
|
Post by rockjunquie on Feb 20, 2018 17:34:38 GMT -5
When I use my Genie, I have spin on wheels for the 50 and 100k. I use those with diamond paste. I hold the dop close to the stone and touch it to gauge the heat. When it is almost too hot to touch, I pop off the stone. Our tap water is super hot. DH put it about 165, which I don't like, but that's pretty hot for tap water. I'm thinking that my stone gets a bit hotter than that. I haven't cracked any stones. I did a fluorite today and I did use the 50 and 100, but I didn't let it get hot. I popped it in acetone. I know all too well what happens when you over heat a fluorite. After I pop off the stone, the glue is usually still a little soft and easy to remove with my snap blade.
|
|
Tommy
Administrator
Member since January 2013
Posts: 12,104
|
Post by Tommy on Feb 20, 2018 18:08:38 GMT -5
|
|
|
Post by rockjunquie on Feb 20, 2018 18:12:52 GMT -5
star bond CA glue. It's like super glue.
|
|
minerken
Cave Dweller
Member since August 2013
Posts: 466
|
Post by minerken on Feb 20, 2018 20:10:00 GMT -5
One thing I have noticed when using acetone is that the amount of glue makes a huge difference if I see glue on the edges of the dop head that's too much with glue I feel less is more. If you think about it if you smear the head with glue you are forming a water tight seal and it takes for ever for the acetone to eat its way through and maybe the center is not effected. I basically don't use any force when trying to remove the cab and use a twisting motion instead of an upward push if it doesn't just pop off then back it goes.
|
|
|
Post by hummingbirdstones on Feb 20, 2018 20:48:57 GMT -5
Boiling the stone and dop will work with CA. Facetors use that technique a lot. I would put the dop and stone in a pot on the stove and bring it to a boil -- let it boil for a few minutes or until the stone falls off. Take the pot off the heat and let it cool down a bit before taking the dop and stone out. If the stone is still on the dop, gently pry around the edge of the stone and it should come off. Let the stone cool all the way down.
The biggest problem with heat sensitive stones is not getting them too hot or too cold, it's stress from extreme temperature change. I dop with wax when I cut opal and I get those puppies pretty hot (too hot to touch). I've never cracked one dopping. Just let them cool down by themselves and all is well.
|
|
Tommy
Administrator
Member since January 2013
Posts: 12,104
|
Post by Tommy on Feb 20, 2018 21:03:37 GMT -5
star bond CA glue. It's like super glue. Thanks. Do you happen to know what model it is? 
|
|
|
Post by rockjunquie on Feb 20, 2018 21:25:45 GMT -5
star bond CA glue. It's like super glue. Thanks. Do you happen to know what model it is? I usually use medium eta the blue label
|
|
|
Post by Pat on Feb 21, 2018 14:54:34 GMT -5
Satellite City answered my query re temperature limits. From Satellite City website (maker of Hot Stuff), in a nutshell, she summed it up: Thank you for contacting us. Cyanoacrylate glue does get more brittle when it is very cold. I have attached a Technical Data Sheet with graphs showing the % strength of the bond at varying temperatures from -50 degrees Celsius to 130 degrees Celsius. Bond strength starts to drop off around -25 degrees. So the bond should not fail unless it is under extreme stress while it is at extremely cold temperatures.
As for applying the glue, cyanoacrylates will be slower to cure (or won't cure at all) at very cold temperatures. So while you can store unopened bottles of CA glue in the freezer to extend the shelf life, it is best to wait for it to warm up to room temperature before applying it.
Celcius to Fahrenheit: -50C =-58F 130C = 266F It never gets that cold or that hot around here. Whew!
|
|
|
Post by rockjunquie on Feb 21, 2018 19:09:38 GMT -5
Satellite City answered my query re temperature limits. From Satellite City website (maker of Hot Stuff), in a nutshell, she summed it up: Thank you for contacting us. Cyanoacrylate glue does get more brittle when it is very cold. I have attached a Technical Data Sheet with graphs showing the % strength of the bond at varying temperatures from -50 degrees Celsius to 130 degrees Celsius. Bond strength starts to drop off around -25 degrees. So the bond should not fail unless it is under extreme stress while it is at extremely cold temperatures.
As for applying the glue, cyanoacrylates will be slower to cure (or won't cure at all) at very cold temperatures. So while you can store unopened bottles of CA glue in the freezer to extend the shelf life, it is best to wait for it to warm up to room temperature before applying it.
Celcius to Fahrenheit: -50C =-58F 130C = 266F It never gets that cold or that hot around here. Whew! Thanks Pat. Good to know. 
|
|