is it just me? getting resin inside the tube

[SantaEric]

my big problem is resin getting inside the tubes...same for alumilite clear and silmar 41...at 40 psi for silmar i get resin inside the tube more often than not after scraping and chipping to clear the tube, just wind up tossing it..just started cutting a wooden dowel, coating with vaseline, inserting into mold, adding vaseline lubed stoppers and 20 psi for alumilite clear....still 50/50 that when i demold that resin will be inside tube....any ideas would be appreciated

 

[hanau]

what mold are you using?
I use the molds made by ptownsubbie and the first time casting with them i had resin inside the tunes.
I re watched his video and started doing what he said and haven't had the problem since.

 

[Sabaharr]

My first thought is that the stoppers might be worn and allowing resin to leak through. If that's not the case you have to find some way to get them to seal better, maybe stick them in further (leading to them wearing more). Whatever it is someone here has been there, done that, and burned the tshirt. You will get a reasonable answer.

 

[jttheclockman]

Once again not enough info supplied. You need to tell us more about the mold and your procedure.

 

[Skie_M]

Try switching to using rubber stoppers ... and fill the brass tube with WATER to prevent a pressure leak? Or you could fill the tube with wax, if you prefer.

 

[jttheclockman]

Try switching to using rubber stoppers ... and fill the brass tube with WATER to prevent a pressure leak? Or you could fill the tube with wax, if you prefer.

Wow have to say I never heard that one. I have had stoppers pop off under pressure. Could you imagine the mess with water in the tube. :biggrin:

OP needs to tell us more about the molds he is using or all else is guess work.

 

[Skie_M]

Well, water won't compress under pressure, so if the tube is filled with water, then the resin can't leak in, right? I think that filling the tube with wax might make a better idea, but getting a good seal and maintaining it under pressure would certainly fix the underlying problem.

 

[jttheclockman]

Well, water won't compress under pressure, so if the tube is filled with water, then the resin can't leak in, right? I think that filling the tube with wax might make a better idea, but getting a good seal and maintaining it under pressure would certainly fix the underlying problem.

Now that is stating the obvious.

I do not use pressure all the time when I cast. All depends on what I am casting. I use those pink formed molds at times and then at times I use silcon stoppers of the PROPER size when casting in tubes.

 

[Sabaharr]

You would think that under pressure the space inside the tube would act like a vacuum due to its lower pressure area. Hence it is sucking in the resin where the seal is compromised. Yeah I know, just stating the obvious again, but trying to jog someone's train of thought and possibly the one with the problem can come up with a solution once they fully understand what's going on.

 

[SantaEric]

ok, my bad...been using the ptownsubbie and the whitish stoppers...when using alumilite i started going down to 20psi and spraying stoner into mold. i sell a good bit of what i make when i'm doing the pre tubed sierra/bolt action blanks but i throw away or spend a fairly equal amount of time trying nullify the afore mentioned problem...i like the way alumilite turns and its durability vs silmar which is also good for different reasons. alumilite is ready to demold a lot faster than silmar but....has anyone used those wax sheets where you press cookie cutter fashion the tube without a lack of adhesion by the resin at the wax contact areas?....so does that clear up things

 

[bobleibo]

I don't do any casting so I'm not sure how it acts up under pressure, but I use wax to seal the ends of my blanks to keep glue out of them. I just buy cheap candles when I happen to see them on sale and use the cookie cutter method. Just be sure to clean any wax off the outside before you glue them in.
Good luck~
Bob

 

[hanau]

ok, my bad...been using the ptownsubbie and the whitish stoppers...when using alumilite i started going down to 20psi and spraying stoner into mold. i sell a good bit of what i make when i'm doing the pre tubed sierra/bolt action blanks but i throw away or spend a fairly equal amount of time trying nullify the afore mentioned problem...i like the way alumilite turns and its durability vs silmar which is also good for different reasons. alumilite is ready to demold a lot faster than silmar but....has anyone used those wax sheets where you press cookie cutter fashion the tube without a lack of adhesion by the resin at the wax contact areas?....so does that clear up things

Did you watch ptownsnubbies video?

After pushing plugs in I pull back on the mold outwards while pushing plugs in.

What probably happening is when you push the plugs in and let go.
The mold pulls back slightly and pulls the plugs lose.

 

[J Michael]

John just posted what I was thinking. My son had the same problem (he didn't watch the video like I told him) and he had the same problem with leaking into the tubes. In case you didn't watch it, here is the link: https://www.youtube.com/watch?v=Vy5kIr9whWE

He hasn't had a problem since he started doing it Fred's way.

 

[jttheclockman]

There you go. I think the last 2 post are your answer to the problem. Also too much pressure collapses the mold around the tubes and then there are spaces at the ends of the tubes. I think you solved that with less pressure as you mentioned. Good luck.

 

[J Michael]

Guess I was thinking faster than I was typing while ago and left out this information ... we use Alumilite (Clear and White) and cast at 50 psi

 

[SantaEric]

i guess my biggest problem with that is that i've got big hands....but...thanks all...