Has Anyone Cast Rattlenake in Alumilite

Signed-In Members Don't See This Ad
A

Arbsmith

Member
Joined
Jan 1, 2007
Messages
74
Location
Aiea, HI, USA.
I've been doing quite a bit of Alumilite casting, and was wondering if anybodyhas tried cating rattlesnake skins in Alumilite? Thanks in Advance.

Dj
 
Signed-In Members Don't See This Ad
Seriously,

Pressure is greatly recommanded. Scales can trap small air bubble and pressure will mostly shrink them to a non visible size.

Work for me. And i know many others have done it.
 
Sorry about that, I meant to come back sooner and enhance my reply, but you know how it goes. If you plan to cast snake skins, you need to find a way to get the air away from the skin before you try to cast it or it will get a silvery glaze on the skin. I have been working with a few ways of getting that done but others have done better with it.
 
I haven't tried yet, but I think that spraying a couple coats of polyurethane onto the skin once it is attached to the tube will help deal with trapped air by sealing the skin. CA of course works for sealing the skin, but I find the CA can be un-even and can turn white..either of these become visible in the cast.
 
Be careful I will not use Alumilite casting snake skin. Some mite remember the fiasco I has when I did a bunch. They looked great after casting there were some problems but they did look good when casted. HOWEVER I found Alumilite how would you say a little more flexible or not as hard the good side that makes it very easy to turn like butter. The down side and this was a HUGH problem wile turning if you squeeze the bushing to tight very easy to do just one catch. Or even when pressing in the parts it will flex the tubes. What happens is the resin separates from the skin on the ends of the tubes and causes an ugly fog that is unrepairable. It cost me $100's that is why I switched to polyester resin. I also believe polyester polishes to a higher gloss finish. Polyester is a little harder and needs just a little more care it can be prone to chipping. But once you get used to it it works just fine.

Just my 2 cents
Bruce
 
bruce119 said:
What happens is the resin separates from the skin on the ends of the tubes and causes an ugly fog that is unrepairable.
Click to expand...

Not that I'm an expert in any of this, but it seems to me that many people
are mistaking 'Set' with 'Cure' when doing resins or Alumilite.
Just because it is hard enough to de-mold doesn't mean cured.

This probably won't matter so much in ordinary castings, but on skins or
labels it can allow the resin to lift, causing the fog you mention.

I see many people talking about turning within an hour or two of pouring.
For skins or labels, I wonder if a post cure might solve this? Or perhaps just
allowing more time for the resin to cure, rather than just time to set.

Just an idea..
 
This has happen to me weeks and months afterward. And anything tried did not fix it. Once it happens your done. The thing is not to let it happen in the first place. There has got to be others out there who has had it happen to them. Just my opinion and experience I will not use Alumilte with snake skin. It's great for worthless wood and other castings but not snake skin.
 
I would tend to agree with Bruce on this one. The Alumilite is very sensitive with the snake skins. Any air will cause a problem and the tube flexing when it is assembled is not something you can really avoid. There is a way to make the Alumilite a little more brittle, but I am not sure of what the long term consequences are yet so i am not going to share the info....YET.
 
Very interesting guys. Alumilite does harden fairly quickly but does continue to cure over the next few days. The chemistry gurus claim it is 72 hours and sometimes more however it is turnable within an hour or so. A durometer tester would tell you whether it has reached its full cure however most people do not have one available to them. Best way to test the cured piece to determine whether it has reached full hardness is to try to stick your finger nail into the 90 degree angeled edge of a cast blank. After casting and before it is fully cured, it is fairly easy to stick your nail into the corner but after it reaches full hardness it becomes quite difficult and a little painful to pick anything off. If the thinner edges are soft, its still not fully cured. Yes it will still turn but is more soft and flexible. Scientific? No, but you will get a sense of feel for it if you haven't already.

In this situation, it is happening even after long periods of time ... good to assume it should be at full hardness. Ed, you mentioned you tried different things. I was curious if you ever tried post curing the blanks after casting? And if you did, did you ever see the separation issue after the post cure? Heat does two things, it helps the resin cure but can also expose issues in the process. Whenever I post cure I put it in an oven at 150 F for an hour to push the back end cure. I'm very impatient and hate waiting for anything. If I have something new I'm either going to add to the resin or embed into the resin I always cast a small sample and put it under some slightly higher heat ... 175-200 F for an hour or two. This is slightly higher than the softening point of our Clear Resin and will often exploit incompatibilities between the resin and whatever it is I'm trying to work with. For example, if its a new liquid addititive, perhaps it will sweat out if it does not crosslink with the resin. It may expose that delaminating issue as well. Is the snake skin porous? It is very important for the resin to wick into and/or saturate the skin. Pressure will force the resin into as much of the skin as possible and dramatically increase the ability to encapsulate it effectively. Using a material with a longer wet/working time may be another reason for the difference in results due to the longer time available for PR to wick into or saturate the skin. If you need a longer open time with the Alumilite resins, we suggest chilling the resins which will extend the open time but make sure to preheat your molds and/or postcure the casting after pouring to ensure a proper cure.

Mike
Alumilite
800 447-9344
 
Mike:
Would you mind if I give you a call and discuss this issue with you sometime? If you don't mind, is there a time which would be better than others?

Thanks
Dennis
 
Glass Scratcher said:
One of the problems with many snake skin castings are that the skins have been coated, treated or "tanned" with a product containing glycerin.
Click to expand...

Good point one I learned very early with many failures rite off the bat. The obvious air looking silver shimmer. And I am casting under pressure 40-50 psi. This was a little over a year ago. What I waund up doing after much discussion is soaking the skins in denatured alcohol for a short period of time. Then wiping then down again both sides before gluing (CA) them to the tube. Then casted them with the Alumilte they looked great I offered to make some for members here and was quickly overcome by orders. I made over 100 they looked fantastic and most every one was happy. Then I started to get some complaints as people started working with them. About 20% and I was able to recreate the problem months after the cast. It mite a combination of things that cause problems. First off I don't think because of the nature of "Rattlesnake" skin the resin can not actually soak in. Also after talking with other well know snake skin casters Rattlesnake skin has air pockets under it's scales (unlike any other skin) that are sealed.


Now with that said perhaps perhaps the problem with separation is due to a couple of things. The resin can not soak in or penetrate the skin to grab it maybe just the nature of the skin. Or the air pockets trapped in the skin although squeezed by pressure and not a visible issue still gives movement when squeezing the bushings or pressing in tight fitting parts.

Mike I like Alumilite I just think it the nature of the Rattlesnake skin. I wonder and I will ask I had this septation after over 6 months. It seam that Alumilite dose not get hard and brittle like a polyester. This is not a bad thing but for example when our pens are turned down there is usually less than 1/32 of resin left on. Now if you were to stretch it (hypothetically) Alumilite would give a little but polyester would just fracture like glass. Another example of my theory take a blank of solid polyester after it is cured throw it on the floor it will shatter like glass do the same with Alumilite it will with stand the shock and not break making me think it is more flexible. Now this is good but for something like the rattlesnake skin that is spongy and doesn't let resin stick to it well may lend the problem. Your thoughts??

Thanks for responding it always nice to have the manufacture check-in.
And I would like to say you are very helpful with answering any questions. You spent a lot of time with me.
Alumilite is a great product.

Thanks
Bruce
 
I appreciate you all sharing your experiences with me as it really helps me understand what you are up against. Dennis, as far as people calling, we welcome it. Is there a better or worse time? I would try mornings (EST) because by the end of the day, things always tend to get crazy. Helping people who are struggling to make whatever it is they are trying to produce is our technical and customer service objective. Use our 800 # and we'll help you with whatever we can.

I will try to look into the glycerine coating or tanning process to figure out if that could be a factor. I understand what you are saying about the hardness but I'm not sure how the hardness alone would make a difference. I agree, the resin may not bond well to the skin itself but it should bond exceptionally well to the cyanoacrylate. Can you tell whether it pops between the CA and the skin or the CA and the resin?? Do you use pure monomer CA (extremely low viscosity - close to water) or a medium viscosity for bonding/sealing the skin? How does the CA cure with the skin ... quickly, slowly, I'm guessing it doesn't haze.

thanks,
Mike
Alumilite
800 447-9344
 
You must log in or register to reply here.
Back
Top Bottom