Getting the resin tight?

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Dale Allen

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I know...what the heck is he talking about.:confused:
This happens more often than not. The resin, Alumilite clear in this case, does not fully contact the label. I am using about 60 PSI and there are no bubbles. The label is a self stick vinyl printed with an inkjet, let dry 2 days, spray on 3 coats of clear acrylic with an hour dry time between. That was left to dry for another day before casting.
I do not have this problem anymore with the polyclay because I now wipe down the clay blanks with paint thinner and let them dry good before casting. Of course, I doubt the ink on this one would have survived that treatment.
Could I maybe solve this by brushing the resin onto the label before I put it in the mold?
Thanks for any help and suggestions.

Dale
 

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Ed, that is actually the roughness on the inside of the blank.
Oddly enough, the brass tube came out of this for reasons I won't get into.
Anyway, I put the blank between centers after scraping a chamfer on the ends of the holes. I cannot detect any bubbles. This is like there is a lack of adhesion between the resin and the label surface. I have some other labels that were prepared differently so I have some other things to try.
 
theidlemind said:
Switch to polyester resin.
Alumilite clear just doesn't work that we'll for embedded casting.
Give it a shot.
Click to expand...

Works just fine on polyclay.
PR stinks up the house and it is too cold outside.
I wanted to make this work so that I wasn't restricted by the seasonal weather here in Ohio! I've done similar with PR months ago and got the same kind of issue.
 
I will agree that alumilite is not the better of the two resins for tube on casting. Maybe the alumilite is not sticking to the clear acrylic which is now next to the alumilite instead of the label paper or vinyl. Do you use the clear acrylic on the polyclay blanks? If so then my suggestion that the alumilite is not sticking to it is overruled.
Do a good turn daily!
Don
 
Don, nothing on the polyclay. Just a swipe with mineral spirits to be sure all contaminants, especially from my fingers, are wiped off.
I've had other instances where the acrylic was not a good bond. Sometimes even CA causes this. It too is a type of plastic so there may be some incompatibility between the plastics. This could be especially true in these cases where one plastic is cured and the other is in it's curing process. Wish I had more knowledge about polymers!
 
TAP Plastics has a clear fiberglass type resin they call surfboard resin that doesn't smell as bad as regular resin. Either that or it fried my sense of smell. I once tried to cast epoxy ribbons in a PR blank and it didn't stick to the ribbons and was told that there was an additive I needed to put into the mix. Unfortunately that is all I know.
 
According to the Alumilite site, if you paint the inside of a mold with laquer, the curing resin will bond to it. Not sure if they mean natural lacquer or the man made stuff.
Maybe a coating of clear lacquer before casting the blank will help. I think I'll ask them.
 
Still not sure what to use as the tube covering yet. I tried another test run and one thing I know is that the vinyl label alone gives the same failure. It could be that the curing process for the resin is not compatible with the vinyl.
 
Dale, since the Alumilite is a urethane based resin, try spraying your decal with a light coat of polyurethane spray all the way around the tube. I've used this in the past and had good results with it. Make sure you pick a quality polyurethane spray though. Krylon has worked for me. Just my .02 cents
 
Thank you Mark. That advise is worth a lot more than 2 cents.:)
I will give that a try. I was also going to try a spray lacquer.

BTW, do you guys really understand and use all those gauges, switches, lights and screens in the cockpit? Or do those things really just kinda fly themselves?:biggrin:
 
I don't know if this will help but I'm thinking the glassy appearance between the tube and resin is not necessarily air but separation. I use pr resin with poly tubes and started using a quality release spray and it helped greatly with that problem. Good Luck. Kenny
 
Kenny, thanks for the info. I agree that it is a separation and not necessarily air bubbles. The separation would be very thin and I suppose there would be some miniscule bit of air there, but hardly any at all. This is the only issue I have left with my pours. They are bubble free and harden as expected. I also considered that it may be something that shows up as I turned the blank but I cannot seem to create any additional shinny spots while turning it to size.
Alumilite, which is what this is, says that lacquer will bond during the cross-link curing action so I am hoping that is the cure...we'll see.
Odd thing is that I don't see this on my polymer clay blanks.
That said, I tried one where I encapsulated the labels within some liquid clay.
Those were heat cured and glued onto a heat cured base wrapped tube. Then the whole thing was coated with more liquid clay and heat cured.
It still did the same thing in various spots.
I've used up about half my resin trying different methods and if I cannot get it figured out soon, it will have to wait until spring when I can do PR again and see if that resin works better.
 
I haven't worked much with alumalite. I started noticing that sometimes the tube would be loose so I tried the liquid release from the hobby stores and it helped but didn't do the trick. I bought an arisol spray and it seems to be working a lot better. I've been casting for several years now and still haven't found a system I comfortable with although I think I'm really close.
 
Kenny, I'm not sure how a release agent would help.
Wouldn't that somehow prevent the tube from sticking to the resin?
Or are you referring to a release on the mold?
I'm not following this at all!
 
Dale Allen said:
Thank you Mark. That advise is worth a lot more than 2 cents.:)
I will give that a try. I was also going to try a spray lacquer.

BTW, do you guys really understand and use all those gauges, switches, lights and screens in the cockpit? Or do those things really just kinda fly themselves?:biggrin:
Click to expand...


Haha! :) All the shiny stuff really does serve a unique purpose. I think every pilot on this forum would agree… when things go south its a great thing when you have backup! ...I'm just a bus driver in the air:biggrin:
 
Yes I'm spraying the release on the mold. I think most of the problems I've been having is that the resin is sticking to the mold and pulling it away from the tube. There were several blanks that were seperated at the bottom of the tube and as the blank cured it would seperate more and more until I had to scrape the whole thing. I also use vertical molds.
 
Kenny, I thank you for that clarification.
Also, that took me completely by surprise.
I would never have considered that the mold may do that and I see now how a release agent would help.
So, I think we need to consider that the urethane resin may be moving or shrinking a minuscule amount and causing the separation. Trouble is I have no way to prove or disprove such a theory.
 
Marko50 said:
Dale Allen said:
Thank you Mark. That advise is worth a lot more than 2 cents.:)
I will give that a try. I was also going to try a spray lacquer.

BTW, do you guys really understand and use all those gauges, switches, lights and screens in the cockpit? Or do those things really just kinda fly themselves?:biggrin:
Click to expand...


Haha! :) All the shiny stuff really does serve a unique purpose. I think every pilot on this forum would agree… when things go south its a great thing when you have backup! ...I'm just a bus driver in the air:biggrin:
Click to expand...

Never had a bus driver I'd trust like I would you flyboys!!:wink: And by the way Mark...saw 24 toms within a slingshot range this afternoon:eek:
 
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Ambidex said:
Never had a bus driver I'd trust like I would you flyboys!!:wink: And by the way Mark...saw 24 toms within a slingshot range this afternoon:eek:
Click to expand...

That's awesome my friend! George, have you ever turned your own turkey pot call? I'm mulling the possibility of casting one. I have no idea of how I would do it, but hey, I'm up for it. Utah's gobbler hunt opens April 12. How 'bout you?:biggrin:
 
I don't think that the release is the only solution, I just know it helps. I still have more failures than I want to admit to but things are getting better. My problem is I don't have the patients I used to so I try too many things at once tring to hurry so that makes it harder to determine whats actually going on. At the rate I'm going in a few more years I should have it down. Ha Ha
 
I have cast alumilite clear pen blanks over acrylic painted brass tube with a cigar label. The label was applied with Mod Podge and sealed with two coats of Mod Podge. The cast was fine. However, when turning the blank several days later, it clouded up as if the Alumilite was not bonding to the paint. Any ide
 
Dale, I have been getting the same results as you. I have use the Avery adhesive backed labels, printed on an ink jet printer. Used the white prepainted tubes which have a smooth finish. Applied the label and let that set for at least 24 hours. First attempt coated with two coats of thin CA and let stand for 24 hours. Mixed the Alumalite, poured into the mold and put in my pressure vessel at ~ 50 lbs. Next day (24 hours) took it out, looks to have cured fine, turn and polish and get the separations or whatever it is. With the second attempt I let the adhesive cure 48 hours, and the CA for 48 hours. Same result. Third try, label cure 72 hours, no sealer. Same result.
 
this thead may be a bit stale but maybe someone will read and offer a solution....tried alum clear under 50psi and still get some clouding...tt alum corp and they said humidity in air may be factor, my shop is not temp controlled...my big problem is resin getting inside the tubes...same for alum clears and silmar 41...at 40 psi for PR...not much, just enough to kill the tube...any ideas would be appreciated
 
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