Hydrocolloid dupclicating issue

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I have been having some problems duping some master models. It seems the duplicated model has a very soft "skin" that sometimes has a powdery residue to it and is not nearly as hard as the master model. I vacuum the air out of green die stone so I'm confident it isn't tiny air bubbles. Any ideas what I'm doing wrong? I'm soaking the master model for at least 10 minutes and I'm melting hydrocolloid in microwave. I've tried the water halfway up method as well as bench cooling and both result the same
 
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I have been having some problems duping some master models. It seems the duplicated model has a very soft "skin" that sometimes has a powdery residue to it and is not nearly as hard as the master model. I vacuum the air out of green die stone so I'm confident it isn't tiny air bubbles. Any ideas what I'm doing wrong? I'm soaking the master model for at least 10 minutes and I'm melting hydrocolloid in microwave. I've tried the water halfway up method as well as bench cooling and both result the same
Have you been:
rinsing the hydrocoloid negative very well before pouring

Heating to the proper melt temp and then after heated cooling to the proper pour temp while stirring.

Ensuring the stone displaces all the water when pouring as the residual water will dilute the stone and create this effect in any impression.

Removing the original model as soon as it is safely certain the hydrocolloid is set up.

Removing the created model as soon as the stone has safely set up.

EDIT: How long are you waiting to move the dup container? Or even to vibrate the bench/shelf it is on? 10 minutes at total rest is the desired minimum for most. With thc GC it sayd to wait 10 and then to cover completely with water if desired.
I am wondering if it getting moved before the initial setting of the hydrocolloid could be confusing the boundary layer between the materials. Hope that makes sense.
 
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Inna-Hurry

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What brand colloid u using?
 
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I'm using "Ticonium Ready MIxed duplicating material". Directions say to allow to cool to 130degrees "if using directly" "otherwise can be used immediately after heating." I didn't touch the dup container ( a steel dup flask) after pouring until the next morning when it was nice and firm. I've done it both ways though - removing as soon as it is cooled (using cold water) and letting sit overnight. I always seem to get the powdery skin on it.

As JMN mentioned, maybe I'm not getting enough water out of the negative? I am rinsing it pretty good though after removing master cast. I pour alginates all the time that are wet with no problem so I didn't think I'd need to completely dry off the hydrocolloid.

JMN, I am not even taking temps...I just cut the colloid into small little blocks, melt in the micro while stirring frequently, and then pour up. Could this happen if I'm getting it too hot in micro? If so, what are the correct temps? The only temp the package mentions is if you are using it directly, which is 130.
 
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I'm using "Ticonium Ready MIxed duplicating material". Directions say to allow to cool to 130degrees "if using directly" "otherwise can be used immediately after heating." I didn't touch the dup container ( a steel dup flask) after pouring until the next morning when it was nice and firm. I've done it both ways though - removing as soon as it is cooled (using cold water) and letting sit overnight. I always seem to get the powdery skin on it.

As JMN mentioned, maybe I'm not getting enough water out of the negative? I am rinsing it pretty good though after removing master cast. I pour alginates all the time that are wet with no problem so I didn't think I'd need to completely dry off the hydrocolloid.

JMN, I am not even taking temps...I just cut the colloid into small little blocks, melt in the micro while stirring frequently, and then pour up. Could this happen if I'm getting it too hot in micro? If so, what are the correct temps? The only temp the package mentions is if you are using it directly, which is 130.

Heat to 190-195F to melt fully and cool to 130-135F for pouring. More instructions inside.
Page 2
https://www.nobilium.com/skin/front...lium_Technique_Manual_40504_Rev_102016_sm.pdf


Try a run following their instrctions on temps and times but using antherrmometer and a dollar store chese grater for uniformity of heat absorbtion.
You need to be using a themometer. Nobody's finger is calibrated that well and I'd not want to try testing 195F stick stuff with a finger anyway.

I'll get you my microwave protcol soon.

Short version:
using a cheese grater get 'enough' in the microweable container. The chese grater gives uniform size so it all heats fairly uniformly. and it is pretty fast too.

Microwaves heatLiquids, sugars and fats moore thsn most other things. We are heating the water in the hydrocolloid so it melts the rest of the contiturnt componenbts of the material. It is like melting a glassfull of water to melt advil gelcaps that are in the water. Which is why you hafe to do defrost settings to let the heat disperse through frozen things which dont vibrate so well at microwave speeds


Microwave 3 minutes ,stir aand check temp. Microwave 2 minutes and stir check temp again. This is usually enough for me to fill a tcs dup flask and have ledt over material.

I am using duplicoeloid by gc which wants are very similar to yours

190 then 140 to 130 for pouring in a pencil sized stream
 
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JMN you are too kind with your time you donate here. I would've asked him to explain his procedure and then you could point out possible problems.
 
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JMN you are too kind with your time you donate here. I would've asked him to explain his procedure and then you could point out possible problems.
Sometimes its just easier to start with what I know works and see what's said are different. No themometer is a big nono. Overheating and overly reducing the water content will make it act so different than it does new. It needs care to do the microwave way, and that's where people get upset and think ill of that path.

And not all materials are quite as amenable to microwaving which is why I say which I'm using. Never could figure out why a friends Bego material was not working well with this process method.
 
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If you ever saw what the denture mills did with their colloid you would understand it is impossible to screw this stuff up.
This guy is REALLY doing something wrong.
OP post up your technique so we can see what it is.
Soft model (even pulled from an impression) ALWAYS equals excessive moisture in the areas the model is soft. True dat.
 
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If you ever saw what the denture mills did with their colloid you would understand it is impossible to screw this stuff up.
This guy is REALLY doing something wrong.
OP post up your technique so we can see what it is.
Soft model (even pulled from an impression) ALWAYS equals excessive moisture in the areas the model is soft. True dat.
I'd back up a bit on the global. Usually? oh indeedy Capt'n Speedy! Always? A solid 'eh'.

There are some sanitizers which if not rinsed out of the impression thoroughly will cause similar appearances of a more chalky or lighter surface.
This was occasionally but not always with a very minute layer of improperly set stone.

When I was primarily a C&B model monkey there was one office who's impressions always had to be extra carefully rinsed for this reason. I believe it was Birex they were using.
Even if you poured it dry, it would still change the model color.

We're playing with chemistry, just simplified some by following the prescribed methods.
Much like cooking. Nobody wonders why the bread didn't come out right when they overheat it and leave out 1/2 the yeast...
 
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"There are some sanitizers which if not rinsed out of the impression thoroughly will cause similar appearances of a more chalky or lighter surface.
This was occasionally but not always with a very minute layer of improperly set stone." Sanitizer residue=MOISTURE. (This is what I was thinking of and happens with Cavicide)

"When I was primarily a C&B model monkey there was one office who's impressions always had to be extra carefully rinsed for this reason. I believe it was Birex they were using.
Even if you poured it dry, it would still change the model color." = MOISTURE film


If the negative is DRY- your model will have no soft spots. A residue of a liquid is considered moisture to me.

ALWAYS.:p
 
JMN

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"There are some sanitizers which if not rinsed out of the impression thoroughly will cause similar appearances of a more chalky or lighter surface.
This was occasionally but not always with a very minute layer of improperly set stone." Sanitizer residue=MOISTURE. (This is what I was thinking of and happens with Cavicide)

"When I was primarily a C&B model monkey there was one office who's impressions always had to be extra carefully rinsed for this reason. I believe it was Birex they were using.
Even if you poured it dry, it would still change the model color." = MOISTURE film


If the negative is DRY- your model will have no soft spots. A residue of a liquid is considered moisture to me.

ALWAYS.:p
I mean dry. As in the only moisture on it was the ambient humidity residue of me and the rest of the worlds' respiration, transpiration, and evaporation.
And 'eh'. I'll agree to disagree on the always, and totally agree on the 99.99987654321%. (did you know 87.452% of statistics are made up on the spot?)
If you spray cavicide and walk away for 60 minutes, it'll be dry.

Anyway. This isn't helping our stranded Wookie. Back to our regularly scheduled insanity.
 
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Craig T

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I have been having some problems duping some master models. It seems the duplicated model has a very soft "skin" that sometimes has a powdery residue to it and is not nearly as hard as the master model. I vacuum the air out of green die stone so I'm confident it isn't tiny air bubbles. Any ideas what I'm doing wrong? I'm soaking the master model for at least 10 minutes and I'm melting hydrocolloid in microwave. I've tried the water halfway up method as well as bench cooling and both result the same
After pouring up the dupe, fold up a damp paper towel and place it on top of the stone. I believe your problem is the hydrocolloid is pulling moisture out of your dupe.
 
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After pouring up the dupe, fold up a damp paper towel and place it on top of the stone. I believe your problem is the hydrocolloid is pulling moisture out of your dupe.

Or vice-versa.... lol!!!!!:pBeer
 
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Ps... I really love this site. Only one with lots of cool peeps!
 
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Ps... I really love this site. Only one with lots of cool peeps!

cool_peep.png
 
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JMN, thank you for the micro details! I will go grab a thermometer and a cheese grater - sounds way better than trying to dice up uniform pieces. So because my directions on the jar say you can use right away after melting, I'm thinking I'm getting it, and pouring it way too hot and just like Craig mentions, it is pulling the water out of the stone or just flat out evaporating it because of heat. I will try pouring at 130 temp tomorrow and let you guys know the results.
Thanks!
Matt
 
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I have been having some problems duping some master models. It seems the duplicated model has a very soft "skin" that sometimes has a powdery residue to it and is not nearly as hard as the master model. I vacuum the air out of green die stone so I'm confident it isn't tiny air bubbles. Any ideas what I'm doing wrong? I'm soaking the master model for at least 10 minutes and I'm melting hydrocolloid in microwave. I've tried the water halfway up method as well as bench cooling and both result the same
had a similar issue when duping via microwave method. bit the bullet and got a dupe machine....zero issues. i know its not the best answer but the machine will pay for itself very quickly. the time/labor invested in microwaving and dealing with issues for 3mo was FAR more than the cost of the (used) dupe machine. food for thought.
 
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Hey All
I'm looking for a Hydrocolloid Dupe machine in good working shape- PM me if you have one to sell.
 
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Quote;
https://dentallabnetwork.com/forums/threads/duplicate-model.6316/post-25410

Alum wash needed possibly. Potassium Aluminium Sulphate. (Not all Gels can be used without a wash). A solution needs to be made up and stored for the purpose. In my experience it's best to have this made up ahead of time for a better quality solution. Pour into mould and leave to stand for a few minutes - there are many opinions as to the timing of this. Pour out and blow off excess, then fill with your gypsum stone material. This should cure the problem.
Prior to pouring gel into the flask for the duplication procedure - soak in warm water, then blow off all excess before pouring gel. If the gel has been poorly handled or overheated, the performance qualities may diminish. If in doubt - contact your supplier for full details on how to get the best from the product.
hope this might help.
 
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