Cast-N-Craft Resin?????

[jttheclockman]

For those that use cast-n-craft resin from Michaels and other places like this I have a few questions. Let me set the scenereo.

I always have been casting in Silmar41 and have great success. Recently I have been having some casting problems doing some sleeve material and I won't go into those here. But what I want to do is try to elliminate my problems trying to use this stuff and see if it makes a difference. I have some laying around and hoping it has not gone bad I will experiment.

My questions are as follows. Do you preheat the resin to elliminate bubbles???? I do this with Silmar and wonder if I can do the same with CNC resin.

Do you use a pressure tank and if so what pressure??? I use a tank with Silmar and keep the pressure at 40 lbs.

How many drops of catalyst are you using without making the blank too brittle or too soft??? I use 4 drops per ounce with Silmar.

Don't worry about temperature. It is being done in a controlled environment.

Do you post heat your blanks the next day?? I like to put my blanks in a toaster oven for about 1-1/2 hours after 24 hours curing on their own. This takes the stickyness out of them and assures they are cured. Can I do this with CNC resin also???

OK you have the questions and hopefully I can get some answers before Monday which is when I want to give this a try. If you have any other tid bits of info I would also like to hear about that too. Thanks in advance for the replys.

 

[ribanett]

For those that use cast-n-craft resin from Michaels and other places like this I have a few questions. Let me set the scenereo.

I always have been casting in Silmar41 and have great success. Recently I have been having some casting problems doing some sleeve material and I won't go into those here. But what I want to do is try to elliminate my problems trying to use this stuff and see if it makes a difference. I have some laying around and hoping it has not gone bad I will experiment.

My questions are as follows. Do you preheat the resin to elliminate bubbles???? I do this with Silmar and wonder if I can do the same with CNC resin.

Do you use a pressure tank and if so what pressure??? I use a tank with Silmar and keep the pressure at 40 lbs.

How many drops of catalyst are you using without making the blank too brittle or too soft??? I use 4 drops per ounce with Silmar.

Don't worry about temperature. It is being done in a controlled environment.

Do you post heat your blanks the next day?? I like to put my blanks in a toaster oven for about 1-1/2 hours after 24 hours curing on their own. This takes the stickyness out of them and assures they are cured. Can I do this with CNC resin also???

OK you have the questions and hopefully I can get some answers before Monday which is when I want to give this a try. If you have any other tid bits of info I would also like to hear about that too. Thanks in advance for the replys.

John,

I use both Silmar and CnC.

I do not use a pressure pot at this time. I have one setting on the shelf for over a year now with a good layer of dust on it. I have had no problems with air bubbles in my castings.

I use 4 drops of MEKP per oz for both.

I do not post-cure my castings, my process is one done in one sitting.

Here is how I do it:

I made a hotbox that give me about 160 deg and enough room inside to put both tube and block molds at the same time.

1. Pre-heat the molds for about 30 min
2. Measure and tint the PR.
3. Pre-heat the PR and add 4 drops of MEKP per oz.
4. Return the PR to the hotbox and remove after about 5 min.
5. Pour into molds and return to hotbox for 1.5 hours.

I turn off the box and allow to cool to room temp.

Done.
The blanks are ready to cut into blanks.

Hope this helps.

 

[jttheclockman]

I guess I can make this like a 2 part question. Here is a quick photo of the problem I am having. It has happened with other materials also than what I am showing.

The top casting is perfect and ready for spinning. The bottom which was in the same batch has some kind of silvering going on for a lack of a better word. I have tried a couple different things when casting these. One I have precoated the outside with a thin layer of resin before casting and the second thing I have done nothing to the outside layer before casting and have gotten the same results either way. Not all castings are bad. Like I said some come out fine. There is no contamination on the sleeving material that I can tell.

Anyone recognize this scenerio when casting and if so what is it and what did you do to correct this. Can't say I have seen this before. Casting is always full of surprises. Thanks for the replys.

When I did this pen again the blank was perfect and it too came from the same roll of material that I am showing. It is a little frustrating to get unprdictable castings especially if it is an order for someone and they are waiting. I like to have things under control so I know the preverbial outcome ahead of time. Sometimes things happen I agree but this is frustrating to say the least.

 

[PenMan1]

John:
I have used CNC when I ran out of Silmar 41.

Yes, I di pre-heat the resin with an ultrasonic cleaner with heat. This worked just like it did with Silmar. I seemed to have a little less working time, but that could have been the change in seasons.

I do use pressure, just like with Silmar. I use 35 pounds of pressure. I use 35 pounds instead of 40 because I get the same results and 35 lbs is easier on my molds.

I add MEKP at 4-5 drops per ounce depending on outdoor temp and humidity.

The only real difference I see between the two resins is that Silmar seems to be clearer and cures with fewer surface bubbles.

 

[DozerMite]

From the pics, it looks like the color is faded or pulled out of the fiber.

What is the fiber colored with? It may be re-acting with the resin.

CC and Silmar are different in many respects. I prefer the Silmar and have used many gallons of the CC before I made the switch.

 

[jttheclockman]

From the pics, it looks like the color is faded or pulled out of the fiber.

What is the fiber colored with? It may be re-acting with the resin.

CC and Silmar are different in many respects. I prefer the Silmar and have used many gallons of the CC before I made the switch.

The black is a nylon fiber which has a high sheen to it and the red is a copper braiding which this also has a gloss to it. . The photo may look a little dull because there is actually a plastic tubing material that I use to cast with surounding the resin. May have caught the light just right to produce that look. I tried to use the blue background to help take the glare away. I don't know how to take a better photo to show it. That is why I posted the pen photo also because you can see in the pen the gloss on the materials.

The effect is somewhat like a crackling look but is not on the entire blank. This side is probably the worst. I have some blanks there is just tiny spots like this but it still does not meet my standards.

 

[ribanett]

John,

I had similar problems with woven tubes, not as bad as in your pictures. I now put the tube on a dowel and wash with a soft toothbrush and Dawn.

I paint PR onto the tubes before putting in the mold. The PR seems to flow better into the holes of the weave. I have very few problems with air bubbles in the weave after washing. Your problem does not look like bubbles but washing may cure it.

I do not use pressure in my casting

Hope this helps

 

[BRobbins629]

I have to agree with Larry. I would bet if you dissected the blank you would see a void around the silvering. This comes from the resin not wetting the surface. The resin is likely beading up in certain portions especially near the nylon. Any source of contamination including grease from fingerprints can cause a problem like this. Washing with solvent or soap and water should help. Have seen and corrected the very same problem with snake skins.

Resin is not the culprit nor is bubbles from dissolved gases. Pressure/heating, etc will not help this one.

 

[its_virgil]

I agree with Larry and Bruce. I have had this problem with snake skin blanks....cast several blanks all done the same way and they all come out perfect except one or two or all of them. Other times they are all perfect. I now clean the skins prior to gluing onto the tubes and again afterwards. Then I paint raw PR on the skins and let them sit for awhile to totally (I hope) soak in and wet the skin. This problem is occurring less often but still raises its ugly head from time to time. I hate it when that happens.
good luck with your casting.
do a good turn daily!
Don

 

[seamus7227]

Hmmm, Don you took the words out of my mouth! Thank you all for commenting and working towards a solution to quality casting!

 

[jttheclockman]

Well I just got back home and thought I would quickly check in here and it looks like a majority of you are suggesting there is contamination and maybe due to fingerprints or oils. I will try wiping down with some sort of solvent. I will try acetone but have to watch for color contamination. If not I will try denatured alcohol. Seems everyone agrees it is nothing I am doing with the casting procedure or the resins. I hope it is that simple. Next week I need to get some of these done for someone so I better figure it out.