Curing in the microwave

[Mine Art]

last week, I had a failed print (part failed to stick due to no support) and decided to experiment a little

after cleaning the model, I put it in a cup of water and microwaved it for 6 minutes
the model seemed came out strong and dry with no shrinkage.

Casted out in 18k white gold just fine

I have only done this once so far but it seems like a decent way to cure models if you are in a hurry rather than 3-4 hours under a UV light

[Yianni-VJ]

I would be a bit concerned to have free radicals floating in my microwave oven...
But a deadline is a deadline, right ? :)
Since you like to live on the wild side, you may try to submerge the model in mineral oil instead of water.
My reasoning is that in should not evaporate, (or maybe it would?) and that any residue does not effect casting.
DISCLAIMER: I have never tried it ! - Do at your own risk !
Good luck ! - Keep us posted :)

[Robert Howle]

Was this with no curing of the model before the microwave?

[benp]

Sounds good, was thinking about curing in the microwave too... good job

[Mine Art]

Quote from Robert Howle on November 19, 2014, 21:29
Was this with no curing of the model before the microwave?

I had just cleaned off the excess resin model with alcohol and soapy water in an ultrasonic, put it in a jar with water and microwaved it for 6 minutes

[Robert Howle]

Thanks, Is it ok to assume the water was boiling for part of the time or not. All microwaves are diff so how long was the boil, and if no boil what temp did the water reach.

Roberf

[Mine Art]

water boiled for about 3-4 minutes, put it in on high and checked around 3 minutes

[Robert Howle]

Thanks for the info. Will do a test.

Robert

[tim.yoshi]

Well one could just cook it in the ordinary pan Boil it for 20 minutes like some pasta or seafood and you're done! :)

Nice thing to try ;)

[Metalcaster]

serving B9 Spaghetti !

[Mine Art]

Done twice more today due to rush jobs needing to be cast tomorrow

Method:
- place ring in glass bowl and cover with plastic wrap
- put in microwave for 3 mins, water was bubbling at this point
- let cool, take out and check
- (optional) clean microwave of water from evaporation
- place in for another 3 mins
- let cool,take out
- done

end result: rings have become hard and dry, while the others from same print sitting in UV box still feel a bit sticky from uncured resin

can post casting results tomorrow

[Robert Howle]

Please do. Had a client that tried boiling in his microwave and ruined his models. What wattage is your microwave? I have not tried yet.

Robert Howle

[Mine Art]

the microwave we use is this one
http://www.danby.com/en/CA/page.php?c=10001&id=14&p=1207
700 watts

casting results of microwaved rings at
http://www.b9c.com/support/?mingleforumaction=viewtopic&t=2284

[tobyramp@hotmail.com]

thank you I will have to try this. I went to the eye doctor today, no glasses yet but I asked about the uv light. He said looking directly at it is very bad. Just being in the same room with the light every day will cause damage due to light bouncing off other surfaces.

[ckl81]

I was testing using microwave to cure my print. I am about cast in an hour. I will post result how it go.

Ken

[RobertW]

I tried curing some (1:1 mix) rings right out of the printer by microwaving them 6 minutes in water and they got small cracks all over. Since then I've found that curing them under UV for an hour or two and then microwaving them in water works just fine. Since we have a 1200 watt microwave, I zap them for 3 minutes, wait 5 minutes and zap 'em again.

[Robert Howle]

Robert, did u notice any diff in your castings?

Robert Howle

[RobertW]

Robert, did u notice any diff in your castings?

Robert Howle

That's hard to say, Robert... the caster is still finding his groove. Things are better now that we're using Doc's but it's pricey so he still uses Plasticast for most gold casting and some results are good while others are disastrous. His latest effort was pretty good... he let it sit undisturbed for 2.5 hr and ramp very slowly to 125 F for 5 hr then shoot straight up to 1350 for 4 hr and 1075 for 3 hr.

On the other hand, Doc's gives very consistent results and I'm thinking complete resin curing is irrelevant and a quick and complete burnout is everything when using it. I'd love to hear others opinions on that, though, since we just started using it.

[Robert Howle]

Curing and burnout are both very important. I have been casting prints for over 1.5 years with just satin cast (bought Plasticast in the beginning and found I didn't need it) I really couldn't tell a dif in casting between the two. You do have to make sure there is adequate ventilation during burnout. Oven must be calibrated to make sure u are reaching 1350 F.

Resin is not forgiving like wax. If u can't cast wax u need to get out of the casting business. If u can't cast resin it is always curing or technique in some way. When it comes to resin everything matters. Bad castings are usually about "ash residue". Three things are key to good castings: Complete curing of the print, Reaching 1350 to 1400 at high end (calibrate oven and controller, some type K thermocoulpes can be off 50 degrees or more), and enough oxygen flow in the oven to facillitate total elimination of the resin. There is also spruing, overheating the metal (swelling), cleaning the metal (flux), etc., but the first three are key.

I have talked to experienced casters who say "Don't worry I can cast anything" then all of a sudden it's the resins fault. I for one know well that after over 30 years of casting in the retail and factory setting, that you cannot be set in your ways. There is change continuously in all industries now, including jewelry. Keep up or get left behind. I choose to try and keep up.

I still learn new things every week, I have never been one not to listen to suggestions. Sharing info and helping others is part of a craftsmans legacy. I for one would like to be remembered as something other than my landlords tennant.

Robert Howle

[RobertW]

Curing and burnout are both very important. I have been casting prints for over 1.5 years with just satin cast (bought Plasticast in the beginning and found I didn't need it) I really couldn't tell a dif in casting between the two. You do have to make sure there is adequate ventilation during burnout. Oven must be calibrated to make sure u are reaching 1350 F.

Robert Howle

I understand that curing, moisture evaporation and burnout are critical factors to successfully casting resin in gypsum-bonded envestments like satin cast and plasticast. I've read that is because uncured resin burns differently than cured resin and emits chemicals that attack the gypsum-bonded fibers and causes them to break down. Since Doc's has no gypsum to break down, I'm wondering if fully curing resin models is necessary when using Doc's.