# Could this be used to cure Alumilite  blanks?



## Gregf (Nov 6, 2020)

I’m a casual label caster. Looking to sometimes speed up the curing time sometimes . Toaster ovens don’t maintain a close enough temp to 150. Does anyone know if this would work? The rotator obviously could be removed. The “laboratory ovens” I’ve seen are way more than what I need. And too big and expensive.










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## jttheclockman (Nov 6, 2020)

Speed up is a very bad set of words in the pen making hobby in my opinion. If you have to speed up production choose to look at different resins then or different methods to do the same thing. Speeding up curing of a product has its downfalls.


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## its_virgil (Nov 6, 2020)

You did not say which alumilite you are using. Alumilite is a brand and not a specific product. They make several resins. I have excellent luck with Alumilite Clear Cast which has a 7 minute open time and will be fully cured in two hours or so. Can't get much faster than that.
Do a good turn daily!
Don


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## Texas Taco (Nov 6, 2020)

I going to guess you're talking about Amazing Clear Cast?  I wouldn't use heat to cure it.  If you want faster cure times swap to Alumilite Clear, it cures in about 90 minutes in a pressure pot.


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## jcimm2000 (Nov 6, 2020)

I use Alumilite Clear Slow. Demold time and cure time are two different things. I demold my blanks after 4 hours in the pressure pot. I let them set for 5-7 days before turning. You can turn sooner; but it really needs about a week to harden enough to take a good shine. You can speed up the process by heating; but I have not tried that method.


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## Gregf (Nov 6, 2020)

I always forget to specify which Alumilite resin.  Either clear or clear slow.

From the Alumilite instructions for clear and clear slow.
_"Demold Time at 75 Degrees F (100g mass) 45-90 minutes (Alumilite Clear) 2-4 hours (Alumilite Clear Slow) 
Full Cure Schedule 5-7 days at room temperature, or *16 hours at 150 degrees F."*_

What I want is something other than a full blown lab oven that will keep a reasonably accurate 150 degree temp for 16 hours safely.

Is anyone familiar with a "Hybridization oven" to know that it will do this ?


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## jcimm2000 (Nov 6, 2020)

Gregf said:


> I always forget to specify which Alumilite resin.  Either clear or clear slow.
> 
> From the Alumilite instructions for clear and clear slow.
> _"Demold Time at 75 Degrees F (100g mass) 45-90 minutes (Alumilite Clear) 2-4 hours (Alumilite Clear Slow)
> ...


Buy a cheap used kitchen oven on facebook marketplace


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## Herman (Nov 6, 2020)

Gregf said:


> I’m a casual label caster. Looking to sometimes speed up the curing time sometimes . Toaster ovens don’t maintain a close enough temp to 150. Does anyone know if this would work? The rotator obviously could be removed. The “laboratory ovens” I’ve seen are way more than what I need. And too big and expensive.
> 
> 
> 
> ...


Hi Greg,
One eletric oven is very useful for several different tasks.  My sugestion, buy a small kitchen oven, double heating (up and dow) and install a precise temperature controle









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Install the controller in to a small plastic box, only temperature sensor inside the oven. You don't need to modify the oven, only connect power plug to temp controller.  It is easy, simple and  very economic.
I'm using this for several years without any problem.


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## JohnU (Nov 6, 2020)

Excessive heat can cause some resins to become more brittle, which will alter the turning process and cause more problems.  I don’t think I would look for ways to speed up the curing but rather find a way to spread out the process and divide the time so your doing other things while the blanks are curing.  In my process I have just enough time to demold and trim the first batch of blanks and set up the next batch while the second batch is curing.


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## Gregf (Nov 7, 2020)

Thanks for the responses, especially the low cost controller option.
I agree it's best to let blanks cure normally.
Occasionally I need one or two quickly. 
Almost all of my castings are TBL pens, sent to LEOs as a result of a news article or Facebook posting on department pages that I follow.
Sometimes for a job well done, especially in the current climate.
Unfortunately sometimes for bad things that happen all too frequently.
I just learned of an officer that was hospitalized as the result of a suicide attempt.
I don't have any TBL blanks ready to go. Usually I do.
I would have liked to have cast it today, turn it tomorrow, get it in the mail on the following day.
Alumilite clear doesn't cure enough overnight to turn and polish in my opinion.


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## Gregf (Nov 7, 2020)

I had thought about the controller on the toaster oven. Since this will sit unattended overnight I would prefer a commercial solution.
SSRs have been known to fail closed.


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## jttheclockman (Nov 7, 2020)

Gregf said:


> Thanks for the responses, especially the low cost controller option.
> I agree it's best to let blanks cure normally.
> Occasionally I need one or two quickly.
> Almost all of my castings are TBL pens, sent to LEOs as a result of a news article or Facebook posting on department pages that I follow.
> ...


The answer to your problem is have other alternatives. Have wood blanks or premade cast blanks weather you made or store bought. If you know you can get into that position then plan ahead with other avenues. Simple as that.


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## Herman (Nov 7, 2020)

Gregf said:


> I had thought about the controller on the toaster oven. Since this will sit unattended overnight I would prefer a commercial solution.
> SSRs have been known





Gregf said:


> I had thought about the controller on the toaster oven. Since this will sit unattended overnight I would prefer a commercial solution.
> SSRs have been known to fail closed.


As I mentioned before, I have been using this solution for a long time, approximately 5 years and without any fail. I didn't change the oven thermostat or the electrical controls. It is not accurate but acts as a temperature limiter in the event of an SSR failure. I also placed a piezo buzzer on the alarm output of the electronic control, set to trigger if the temperature exceeds a certain limit.
I believe that the operation is safe considering the double redundancy in failure mode, limiter + alarm. Even commercial equipment also has limitations and can present problems. Whatever the chosen solution, security is very important, I recommend a lot of care and attention with equipment and processes.


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## ramaroodle (Nov 7, 2020)

I wouldn't worry too much about the failure of a toaster oven.  Use one of those cheap internal oven thermometers and get the oven to your desired temp. I leave my $8 Goodwill toaster oven on overnight all the time when I'm cooking stabilized blanks. If you're worried about a fire hazard by leaving it on overnight put it in the middle of the garage floor.  150 degrees isn't really hot like a furnace, it's only a little hotter than a summer day in Arizona.


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## ramaroodle (Nov 7, 2020)

A $179 hybridization oven seems like overkill to me.


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## Gregf (Nov 7, 2020)

ramaroodle said:


> A $179 hybridization oven seems like overkill to me.


He lowered the price to $150, then to $75 privately when he discovered cosmetic issues.


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## ramaroodle (Nov 7, 2020)

Gregf said:


> He lowered the price to $150, then to $75 privately when he discovered cosmetic issues.


Still a lot more than a Goodwill toaster oven and a $2 themometer, but $75 is probably a good price for an oven like that, but I don't know.  Although the listing now says sold.  Did you buy it?


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## chartle (Nov 7, 2020)

Herman said:


> Hi Greg,
> One eletric oven is very useful for several different tasks.  My sugestion, buy a small kitchen oven, double heating (up and dow) and install a precise temperature controle
> 
> ....



Thats what I use but not to speed curing. I first made this to control my bbq smoker(controlling a small fan) and then my toaster oven to cure stabilizing juice. Heat sink really isn't needed but I also was going to try sou vie(sp?) Cooking and it would be heating up a large slow cooker.

I set the temp on the toaster oven just a little higher then set temp just in case.


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## ramaroodle (Nov 7, 2020)

Gregf said:


> I always forget to specify which Alumilite resin.  Either clear or clear slow.
> 
> From the Alumilite instructions for clear and clear slow.
> _"Demold Time at 75 Degrees F (100g mass) 45-90 minutes (Alumilite Clear) 2-4 hours (Alumilite Clear Slow)
> ...


Still think you guys are overthinking this but that's just me. 45-90 min and 2-4 hours and 5-7 days and 16 hrs are intervals times and temps you could drive a train through so I doubt that 10-20 degrees one way or the other are really that critical.  Any cheap toaster oven with an oven thermometer in it should be all you need.  You cant "over-cure" it.


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## Herman (Nov 7, 2020)

ramaroodle said:


> Still think you guys are overthinking this but that's just me. 45-90 min and 2-4 hours and 5-7 days and 16 hrs are intervals times and temps you could drive a train through so I doubt that 10-20 degrees one way or the other are really that critical.  Any cheap toaster oven with an oven thermometer in it should be all you need.  You cant "over-cure" it.


Well, for me this small oven has multiple functions and is very useful: vulcanizing silicone molds, drying PU varnish, annealing acrylic parts, reducing viscosity of epoxy based resins, removing air bubbles,  fixing cataphoretic varnish...
Temperature stability and reproducibility is essential.


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## ramaroodle (Nov 7, 2020)

Herman said:


> Well, for me this small oven has multiple functions and is very useful: vulcanizing silicone molds, drying PU varnish, annealing acrylic parts, reducing viscosity of epoxy based resins, removing air bubbles,  fixing cataphoretic varnish...
> Temperature stability and reproducibility is essential.


Yes. I guess if you're gonna use it for those things $75 is a bargain.  The OP said he was a casual caster and I have no idea what cataphoretic varnish is.


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## Herman (Nov 7, 2020)

ramaroodle said:


> Yes. I guess if you're gonna use it for those things $75 is a bargain.  The OP said he was a casual caster.


To be honest, I made some improvements to my cheap oven. Thermal insulation was not the best and I added rock wool internally. Reduced energy consumption and heat generation within the workshop. This allows me to work comfortably and safely up to 360 F degrees. I also have another muffle furnace for high temperature, 1800 F degrees used in metal casting  and the principles are the same, only the controller is more sophisticated allowing heating / cooling ramps.


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## chartle (Nov 7, 2020)

One other thing I put my blanks on top of the fridge . Its a nice gentle warmth.


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## Herman (Nov 7, 2020)

ramaroodle said:


> Yes. I guess if you're gonna use it for those things $75 is a bargain.  The OP said he was a casual caster and I have no idea what cataphoretic varnish is.


Cataphoretic is a type of protective varnish applied on silver and other metals, very resistant. sorry


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## ramaroodle (Nov 8, 2020)

Herman said:


> Herman said:
> 
> 
> > Cataphoretic is a type of protective varnish applied on silver and other metals, very resistant. sorry





Herman said:


> To be honest, I made some improvements to my cheap oven. Thermal insulation was not the best and I added rock wool internally. Reduced energy consumption and heat generation within the workshop. This allows me to work comfortably and safely up to 360 F degrees. I also have another muffle furnace for high temperature, 1800 F degrees used in metal casting  and the principles are the same, only the controller is more sophisticated allowing heating / cooling ramps.


Thanks.  Way above my pay grade!


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## Gregf (Nov 8, 2020)

ramaroodle said:


> Thanks.  Way above my pay grade!


Always interesting, the direction a thread can take.


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## McKenzie Penworks (Nov 30, 2020)

Yikes... a lot of bad information in this thread.

First: Heat curing is NOT bad. It also, in many cases, strengthens a urethane vs making it more brittle. Alumilite Clear (and Clear Slow) is actually fairly unique in the urethane world because it does cure so hard at a room temperature. Heat curing it (per the instructions on their website...) just gets you to full hardness in 14 hours instead of 7 days. You will not be sacrificing any benefits by curing it that way.

Toaster ovens, etc are not good choices for heat curing. They tend to have hot spots, don't really hold heat well, and you've got an element that's technically hotter than the air temp around it with not a lot of air flow. Same thing with traditional ovens... I get it, they're cheap... but they are the wrong tool for the job.

Best choice is a forced air curing oven. Examples would be by Despatch, Cascadetek, etc. They are expensive but you can guarantee they hold the temp steady and the constant air flow means every corner is roughly the same temp. Even better, they can be programmed to run cycles with a press of a single button. They are also great for drying and curing for stabilizing without a risk of a fire hazard. (I've seen way too many shops burned down by people trying to use smokers and toaster ovens...)

We currently run a TFO-5 Cascadetek oven here in the shop for curing everything and will be upgrading to a bigger one as we look at more high performance ovens. On the used market you can save thousands... so be on the look out there to save some money but expect to pay more than $100  Since buying that oven we use it for everything from drying wood to curing the epoxy on glue ups faster. It's been AWESOME to have.


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## greenacres2 (Nov 30, 2020)

Got to agree with Tim on using a toaster oven for pretty much anything but toast.  To be safe, i bought a new one, brand name.  Even after adding a PID controller--in order to come close to maintaining 190-f, had to set the PID to something like 158 on and 162 off.  After the burners turned off, the temp would rise from 162 to over 400--got pretty good control for curing Cactus Juice, but set fire to a batch of buckeye burl one night trying to dry it.  Thankfully, it was in a detached garage--which somehow didn't burn down.  Has not been used since.  Ended up buying a used analog lab oven on the auction site, has a lot of mass so it takes a while to heat up, but holds in a 5 degree range for 2 days.  And...runs on amazingly few amps (rated at 4.2 amps, 120 volt, at full power).
No toaster oven for me--ever!!
earl


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## McKenzie Penworks (Nov 30, 2020)

Buddy of mine nearly burned down his brand new house 2 weeks ago with one of the electric smokers... Had it full of wood. Had a neighbor not noticed some smoke coming from the back deck and investigated there's a very good chance the entire house would have gone. I'm amazed at the risks folks will take to save a buck.....


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