Alumilite versus poly-resin casting...help!

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yorkie

yorkie

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Joined
Mar 2, 2009
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Charlotte, North Carolina
I'm about to step off that cliff into analysis to paralysis. Help!!

I want to get into casting and see myself doing amalgam casting mainly, but also trying regular color casting.

What is best? Alumilite or poly-resin? Do I need a pressure pot and vacuum pump? if so, where and what is good so I don't spend too much for the occasional casting I'm going to be doing.

Thanks a lot, guys. I always appreciate the feedback.

I have a ton of extreme figure Cherry burl that would be great as amalgam casting.
 
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If your main goal is casting burl pieces then alumilite is your best bet. It will adhere to wood MUCH stronger than PR will. You MUST use pressure for this though, no matter which resin you choose. There are many topics about what pressure pot is best so you'll get many different suggestions with that. My best advice is do your research on PSI ratings and customer feedback. Here's a site I'm looking at for myself: http://www.paintsprayersplus.com/category/14_1_pressure_pots/. The only downside to alumilite is the price, it's more than twice as expensive as PR. There will be a learning curve so I wouldn't try your best wood 1st. Alumilite is super sensitive to moisture so if the wood being cast isn't completely dry the resin will fail and fail miserably. Curtis posted some alumilite videos not long ago, watch those as he explains the in's and out's of using it.
 
How do you feel about the harbour Freight 2.5 gallon pressure pot?

http://www.harborfreight.com/2-1-2-half-gallon-pressure-paint-tank-66839.html



Brooks803 said:
If your main goal is casting burl pieces then alumilite is your best bet. It will adhere to wood MUCH stronger than PR will. You MUST use pressure for this though, no matter which resin you choose. There are many topics about what pressure pot is best so you'll get many different suggestions with that. My best advice is do your research on PSI ratings and customer feedback. Here's a site I'm looking at for myself: http://www.paintsprayersplus.com/category/14_1_pressure_pots/. The only downside to alumilite is the price, it's more than twice as expensive as PR. There will be a learning curve so I wouldn't try your best wood 1st. Alumilite is super sensitive to moisture so if the wood being cast isn't completely dry the resin will fail and fail miserably. Curtis posted some alumilite videos not long ago, watch those as he explains the in's and out's of using it.
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That's a whole different animal. Yes many here use them daily without a problem. Others, well they've been lucky to not get their faces blown off when it failed. Curtis's failure best comes to mind. Personally, I have one and have used it from time to time and I'm switching to a much safer rig. The quality just isn't there and I don't like the sound of a 40PSI failure to the face, lol.

Ebay or Craigslist has Pressure pots for sale all the time. You can check there. If you go the craigslist route try to get the owner to do a pressure test with you there before buying!
 
yorkie said:
How do you feel about the harbour Freight 2.5 gallon pressure pot?

http://www.harborfreight.com/2-1-2-half-gallon-pressure-paint-tank-66839.html
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Many of us use that pot. I use it myself. Some people have had the pot fail under pressure. As the story comes out, however, these tend to be situations where the pots were modified in some way that promoted the failure, safety features were not used, and/or the pots were overpressurized.

Like any other tool in the shop, use it smart and it will work for you.
 
Brooks803 said:
That's a whole different animal. Yes many here use them daily without a problem. Others, well they've been lucky to not get their faces blown off when it failed. Curtis's failure best comes to mind. Personally, I have one and have used it from time to time and I'm switching to a much safer rig. The quality just isn't there and I don't like the sound of a 40PSI failure to the face, lol.
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Curtis' failure is a perfect example of a pot that failed due to the actions of the caster, not a design problem with the pot itself. As I recall, he modified the lid in a manner that allowed one of the clamps to slip, leading to pot failure. He is the first to admit that his failure was do to his modification, not an inherent design problem with the pot itself.
 
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Thanks, Steve. What kind of pump do you use?


sbell111 said:
Brooks803 said:
That's a whole different animal. Yes many here use them daily without a problem. Others, well they've been lucky to not get their faces blown off when it failed. Curtis's failure best comes to mind. Personally, I have one and have used it from time to time and I'm switching to a much safer rig. The quality just isn't there and I don't like the sound of a 40PSI failure to the face, lol.
Click to expand...
Curtis' failure is a poor example. As I recall, he modified the lid in a manner that allowed one of the clamps to slip, leading to pot failure. He is the first to admit that his failure was do to his modification, not an inherent design problem with the pot itself.
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Steve that's true, but unless they've changed since I got one last year all the HF pots have to be modified in the first place to be usable for what we want to do with it. I have one myself. Again, all I'll advise is to do research on the different pots to find what is best for you.
 
Brooks803 said:
Steve that's true, but unless they've changed since I got one last year all the HF pots have to be modified in the first place to be usable for what we want to do with it. I have one myself. Again, all I'll advise is to do research on the different pots to find what is best for you.
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Jonathan, do you pressurize all of your castings?
 
I did use a HF pressure pot and the only modifications made were to seal off the paint tube, etc to make it work for casting. It was NEVER filled over half way to its 80 PSI listing. It exploded, wrecking my shop and nearly killing me.

To my knowledge, HFs pots are not certified or tested by any scientific community. Additionally, just looking at these pots in the store, the quality seems to vary from pot to pot.

Having the experiences I've has, I WOULD NEVER AGAIN USE ONE OF THESE INFERIOR POTS. If I didn't have enough volume to justify a tested and rated pot such as Binks or Divillbus, I would hire someone to do my casting and stabilization for me.

I guess the bottom line question is: "How much is your life worth?"
In my case the answer to that question was "considerably more than the $35 more than it cost me to upgrade to a used, rated and tested Binks pot".
 
Brooks803 said:
Steve that's true, but unless they've changed since I got one last year all the HF pots have to be modified in the first place to be usable for what we want to do with it. I have one myself. Again, all I'll advise is to do research on the different pots to find what is best for you.
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If you do a forum search, you will find several mentions of the 'pot savers' that Curtis was using with his pot. That kind of modification is what I was refering to, not the routine modifications that we do to convert the product from being a paint pot to a pressure vessel.
 
I can't speak to Andy's experience as I wasn't there and I don't recall his original telling of the story.

Use any of your tools responsibily with an eye for things can go wrong. For instance, with a pressure pot, never modify the way in which the clamps work. Always have a safety valve on the pot properly dialed in to ensure that the pot isn't over pressurized. Similarly, dial in your compressor's output pressure regulator for a bit of insurance. Use care to ensure that all of the clamps are secure prior to pressurizing the tank. Leaving one clamp just a bit loose will cause a failure in the best tank and you'll never know why. (Leaving one to blame the tank.) Finally, respect for your tools also means knowing where to be when they are in use. Just as you wouldn't stand directly in front of the table saw while it's in use, don't spend time around the business end of a pressurized vessel, either. My pressure pot lives far on the other side of the shop when in use. Sometimes, I even put it outside.
 
All great advice, guys. I went by HF today to look at their pot and it looks sturdy enough but, the story of the pot exploding with only 40psi in it kinda put the budget in perspective. I think I'll spend a little more and get a better pot than the HF pot.

You guys rock!!

Now, what kind of vacuum pump should I get again? 2.5cfm, 4cfm, 6cfm, 1 stage, 2 stage??
 
It sure looks like the HF pot painted black and put on rollers.

Personally, I check the local pawn shops. A lot of painters pawned their tools during this economy. You may find a Binks for $100 or so. Much better pot.
 
You think a used Binks would be better than a new Grizzly? This one had a pressure relief valve which seemed like a good safety feature.



PenMan1 said:
It sure looks like the HF pot painted black and put on rollers.

Personally, I check the local pawn shops. A lot of painters pawned their tools during this economy. You may find a Binks for $100 or so. Much better pot.
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All the pressure pots should have a pressure relief valve, if it doesnt dont use it.

If your not in a rush finding one, look at yard sales and estate sales also. I got my binks pot at a yard sale for 25.00.
 
Absolutely, I think a Binks would be better than the Grizzly pot. The Binks is an "industry standard" certified to 80 PSI WORKING PRESSURE.

The Grizzly is a Chinese pot that most likely comes right out of the same factory as the HF pot.

Many of the Grizzly tools (wood lathes, included) are the same tools as HF with just a label change>
 
Okay, Andy. you've convinced me. I'll keep my eyes pealed for a used Binks.

Thanks for all the time.

Lastly, what vacuum pump CFM shall I buy?


PenMan1 said:
Absolutely, I think a Binks would be better than the Grizzly pot. The Binks is an "industry standard" certified to 80 PSI WORKING PRESSURE.

The Grizzly is a Chinese pot that most likely comes right out of the same factory as the HF pot.

Many of the Grizzly tools (wood lathes, included) are the same tools as HF with just a label change>
Click to expand...
 
yorkie said:
Okay, Andy. you've convinced me. I'll keep my eyes pealed for a used Binks.

Thanks for all the time.

Lastly, what vacuum pump CFM shall I buy?


PenMan1 said:
Absolutely, I think a Binks would be better than the Grizzly pot. The Binks is an "industry standard" certified to 80 PSI WORKING PRESSURE.

The Grizzly is a Chinese pot that most likely comes right out of the same factory as the HF pot.

Many of the Grizzly tools (wood lathes, included) are the same tools as HF with just a label change>
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Click to expand...

That's a question I'll defer to Curtis. Mesquite Man is our resident stabalization expert.

The one I have was "inherited" from a retired HVAC guy. I wouldn't even know where to start looking today.
 
Absolutely! I suspect the Griz and the HF both come from the same Mainland China throw it together and get it out the door facility!!! I have a HF and even well above 50 PSI I have not had a problem "YET" That does not mean that I can not have a problem. I have begun using the HF for vacuum, as I'm not really too scared of being beheaded by an implosion. I have a C A Technologies pot that I use for pressure. You can just look at the difference between the two and you will quickly recognize which one you would feel comfortable laying down beside and going to sleep.
yorkie said:
You think a used Binks would be better than a new Grizzly? This one had a pressure relief valve which seemed like a good safety feature.



PenMan1 said:
It sure looks like the HF pot painted black and put on rollers.

Personally, I check the local pawn shops. A lot of painters pawned their tools during this economy. You may find a Binks for $100 or so. Much better pot.
Click to expand...
Click to expand...
 
If you are looking for a vac pump for casting, save your money. I have done a lot of experimenting with using vacuum only, vacuum and then pressure, and just pressure and pressure works better than vacuum only and just as good as vac/pressure. THIS IS FOR CASTING.

For stabilizing, it is exactly the opposite. Vacuum is absolutely needed for home stabilizing. Pressure will not do much on its own and has very marginal improvement after vacuum. This is based on home shop type equipment and from lots of controlled experiments. In my experience, pressure after vacuum when stabilizing only added 3.7% weight whereas the vac cycle before added 65% weight gain. This was based on a controlled study of 10 different wood pen blanks.

Now, back on topic...if you are going to be stabilzing, then you really want to look for a rotary vane vacuum pump. This is the type that refrigeration and HVAC technicians use. This will generate the best vacuum for the money. Look for something rated at 29" Hg or 75 microns or less. don't worry too much about CFM ratings. Higher CFM rated pumps will NOT pull a deeper vacuum, they will just do it quicker. Then again, you are limited by the diameter of the hose that you use and most likely will never benefit from a higher CFM pump when stabilizing.
 
So, to be clear, for casting and making wood/alumilite blanks, I will be in good shape with a pressure pot and I can use my air compressor to pressurize the pot, rather than buy a vacuum pump to suck out the air.

Did I understand you correctly?


MesquiteMan said:
If you are looking for a vac pump for casting, save your money. I have done a lot of experimenting with using vacuum only, vacuum and then pressure, and just pressure and pressure works better than vacuum only and just as good as vac/pressure. THIS IS FOR CASTING.

For stabilizing, it is exactly the opposite. Vacuum is absolutely needed for home stabilizing. Pressure will not do much on its own and has very marginal improvement after vacuum. This is based on home shop type equipment and from lots of controlled experiments. In my experience, pressure after vacuum when stabilizing only added 3.7% weight whereas the vac cycle before added 65% weight gain. This was based on a controlled study of 10 different wood pen blanks.

Now, back on topic...if you are going to be stabilzing, then you really want to look for a rotary vane vacuum pump. This is the type that refrigeration and HVAC technicians use. This will generate the best vacuum for the money. Look for something rated at 29" Hg or 75 microns or less. don't worry too much about CFM ratings. Higher CFM rated pumps will NOT pull a deeper vacuum, they will just do it quicker. Then again, you are limited by the diameter of the hose that you use and most likely will never benefit from a higher CFM pump when stabilizing.
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