jttheclockman
Member
Will casting resin harden on its own without adding the hardener??? I am using Simlar41??? If so how long are we talking and can I spped it up by placing in an oven??? Has anyone tried this??? Thanks
Resin
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PTownSubbie
Member
Never tried it but I think it will work.
By theory, the MEKP only starts a reaction that produces heat and it is heat that cures the resin. Therefore, if you put it in the oven it should harden. Temp about 170F but it will stink up the house......Toaster oven in the workshop works great!!
By theory, the MEKP only starts a reaction that produces heat and it is heat that cures the resin. Therefore, if you put it in the oven it should harden. Temp about 170F but it will stink up the house......Toaster oven in the workshop works great!!
PR_Princess
Member
Most PR is pre-promoted. Meaning that it already has a small amount of the catalyst in it. It will set if exposed to enough heat over a long enough period. However, I would not recommend it. It would be better to add in the MEPK.
It doesn't have the catalyst in it, it has an accelerator(cobalt napthanate) in it and when the catalyst(MEKP) is added, it creates a chemical reaction that makes the heat.
Yes, it will cure without the catalyst. Put the can in a warm place and you'll see.
Why are you not wanting to add the catalyst?
Yes, it will cure without the catalyst. Put the can in a warm place and you'll see.
Why are you not wanting to add the catalyst?
jttheclockman
Member
I want to use it as a paste so the amount I am using is very minimal and I am thinking if I add catalyst to it that it may make it too hard. I did not want to make more than I need.
JohnU
Member
Not sure how you would get it to paste form without it curing on you too fast. I keep mine in the basement where it stays nice and cool in a thick syrup like form. The problem with it being cold is it takes longer to cure, and when its done, the top will be very sticky or gooey, so you will need to heat it anyway. I use a pressure tank and put it infront of my heat vent upstairs so it heats the tank air as it cures. Not as sticky then. About 5 minutes in the oven on warm and let it cool usually fixes the sticky surface for me.
Not sure what your casting but add water to your mold in the amount of resin you want to use and then pour it into a measuring cup to see how much there is (so you know how much catalyst to add), then pour it in a clear plastic cup and draw a line on the outside so you know when to stop pouring resin. From there you can pour from the first cup to others for making a multiple color pour. Just make sure everything is dry and water free before you use your resin.
jttheclockman
Member
I tried epoxy but had problems with clumping and not even coverage of what I want to do. I may give it a try. It is not big lose if it doesn't work.
John
The reason I did not want the catalyst so that it doesn't kick so fast because it will be such a thin layer so that is why I was hoping it will harden on its own. I am going to give it a try and see what happens.
workinforwood
Member
Inlace will cure faster in thin layers than PR will. You still want to add some hardener though. Inlace can be spun on the lathe when it's all done. Epoxy will not spin well on the lathe. If you made a pen blank from just epoxy, it would get all soft and gooey on you from the heat of a chisel. Plus..epoxy will yellow quite a bit over time, so it's not a good choice for the outside of a pen, with the exception of filling a few holes in a blank...it is good for that. If you must use PR and want a super thin layer on something like a snake skin perhaps, then you can brush the PR on real thin and stand the tubes on a cookie sheet and bake them in the oven with or without calalyst.
PenMan1
Member
Silmar will harden without catalyst.
Silmar 41 (and I suspect all other PRs) will harden without adding MEKP. I discovered this by leaving the shop in a hurry and leaving the top off of a gallon can of S41 with about 2" of resin in the bottom. I went back a couple of weeks later and the resin was hard.
Silmar 41 says on the product information sheet that the shelf life for unopened cans is six months. In reality, I have left opend and carefully resealed 41 on the shelf for over a year and it was still fine.
Now that my pressure pot is dead, I always use a wal-mart $15 toaster oven set at 150 degrees. Under usual shop conditions, the oven will "set" properly catalysed PR in 3/4 by 3/4 x 5 inch blue silicone pen mold in less than 1 hour. Be careful to check your mold often (the molds I use are $25 each.
I am sure the oven will "set" even uncatalysed PR but I don't know how long (days, I'm sure) it would take.
I hope this helps.
Silmar 41 (and I suspect all other PRs) will harden without adding MEKP. I discovered this by leaving the shop in a hurry and leaving the top off of a gallon can of S41 with about 2" of resin in the bottom. I went back a couple of weeks later and the resin was hard.
Silmar 41 says on the product information sheet that the shelf life for unopened cans is six months. In reality, I have left opend and carefully resealed 41 on the shelf for over a year and it was still fine.
Now that my pressure pot is dead, I always use a wal-mart $15 toaster oven set at 150 degrees. Under usual shop conditions, the oven will "set" properly catalysed PR in 3/4 by 3/4 x 5 inch blue silicone pen mold in less than 1 hour. Be careful to check your mold often (the molds I use are $25 each.
I am sure the oven will "set" even uncatalysed PR but I don't know how long (days, I'm sure) it would take.
I hope this helps.
its_virgil
Member
The six months shelf life given by most manufacturers of PR is from the time it was manufactured, not from the time it was sold or opened. The time it sits on the store shelf or in a warehouse is time counted in the 6 months. And, yes, I've had PR stay good for several months and even over a year and other times PR has become useless for casting(clear casting is all I do) in just a month or two. One brand even formed small pellets of soft jelled PR and those pellets did not harden when I made blanks. While turning the blanks I would turn into soft sticky spots of uncured PR. This brand was not Silmar 41. Do a good turn daily!
Don
Don
Sberger
Member
If you want a paste or running type plastic, here is what you can do. Materials needed is scrap plexiglass, Acetone, mason jar with air tight lid. Break up the plexiglass in small pieces and put in the jar and add acetone. In a couple of days it will be a sticky, gooey, kind of heavy plastic liquid.
Steve
Steve