casting questions.

[amosfella]

I have a few question about casting. I had tried to use autobody PR as a casting resin, and use acrylic paint as a coloring agent. When I did that, the PR hadn't cured in 24 hours. I used 25 drops of MEPK in about a 5x5x7/8 mold sized pour. It wasn't curing, so I did the same thing again, adding more PR, and still using acrylic paint. The top half hardened, but the bottom stayed soft. On the 3rd try, I used 60 drops, and it hadn't hardened at all.
I'm doing this in a heated shop, that's about 68 degrees. Is the autobody PR not suitable for casting??
Where is a good place to buy Alumilite if that is recomended that will ship to Canada?
Has anyone tried epoxy casting resin, or acrylic resin??
Has anyone tried coating tubes with the clear epoxy finish used on bars and such high wear areas that you aparently can cast coins and such under??
Thanks for your answers in advance.

 

[maxwell_smart007]

Alumilite ships to Canada - buy directly!

Andrew

 

[amosfella]

What are the customs charges on the 2 gallon one??

 

[gwilki]

You might want to try hobby shops in your area. Look on the alumilite site. They show dealers in Canada. I get mine from a hobby shop here in Ottawa, listed on the alumilite site.

 

[Glass Scratcher]

What is the minimum working temperature for the PR you are using? Even in a 68deg shop you may be below the optimum minimum cure temp. Lower temperatures can cause thermal cure inhibition. The paints you are using as a pigment can also cause cure inhibition. The quantity, that is, too much paint used to pigment your PR can cause cure inhibition. Place your castings in a warmer environment and be patient.

 

[amosfella]

I guess I'll have to warm the shop up to 75. So, Acrylic isn't a problem??

 

[Glass Scratcher]

Many of us use Polyester resin. I use Silmar 41 by Interplastics. I am looking at Silmar 40. But I have also heard very good reports about polyester "Swing" resins.

Some unfortunate, impatient soles use Alumilite and other PolyEurethane resins. :befuddled:

You don't have to necessarily heat the entire shop up to above 72deg. You could build a warmer/hotbox out of thermalcore, or durarock(concrete board) and heat it with a incandescent lightbulb. Have a probe thermometer, and some venting to keep it from getting too hot. For post curing you can shutter your vents some and move the temp above 100deg F for an hour or 2, depending on what your tech sheets say the deformation temp is for your resin.

 

[amosfella]

Well, I did order some Slimar 41 from US composites. It's not here yet, but I hope to get it soon.
As for heating the shop a bit more, it's a cola fired self stoking furnace. Not a big deal. We get the coal by the semi load anyways.

 

[Glass Scratcher]

With S41 you should be able to get plenty of help around these parts.

 

[sbell111]

You should not have a huge problem with S41 at your current temeratures, if you change what you are using to color the resin. I think that the acrylic paint is inhibiting your cure. If you went to one of the dry pigments that are available, you likely would be fine.

I cast some money blanks in my garage the night before last. It was pretty chilly in teh garage over night, probably around 60 degrees. I let them set up all night and checked on them yeaterday when I got home from work. They were set up completely, but still asticky on the outside, so I moved them to the kitchen. (Cathy's out of town until today). An hour or so in our 68 degree kitchen and they were perfect.

 

[sdemars]

You can add a . . . .

Many of us use Polyester resin. I use Silmar 41 by Interplastics. I am looking at Silmar 40. But I have also heard very good reports about polyester "Swing" resins.

Some unfortunate, impatient soles use Alumilite and other PolyEurethane resins. :befuddled:

You don't have to necessarily heat the entire shop up to above 72deg. You could build a warmer/hotbox out of thermalcore, or durarock(concrete board) and heat it with a incandescent lightbulb. Have a probe thermometer, and some venting to keep it from getting too hot. For post curing you can shutter your vents some and move the temp above 100deg F for an hour or 2, depending on what your tech sheets say the deformation temp is for your resin.

You can add a chicken coop thermostat for about $12.00 . . . . that will maintain temp within 10 degrees . . . .