Acrylic or Resin pen blanks.

Drew Croy

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I've been reading for several days on on the procedures for making acrylic or resin pen blanks. One thing seems to be re-occurring over and over: pressure or vacuum?

Although I have a nice set of plans for using a pressure pot from Harbor Freight, I've also seen some really nice vacuum set-ups but haven't been able to find any decent plans for making one of those.

It would seem to me that you would get less mess using a vacuum, but maybe it's A lot cheaper to use a pressure system?

I need your input here as this is the ONLY place I go when I'm stuck.
 
Good source for PR

Ok, I was waiting for a reply I seem to have answered my own questions and I'll be going with a pressure system made from a paint pot.

I have more question though.

Where is a good place to order Polyester Resin? I also noticed that it says it will not fully cure when exposed to air. If it's in the paint pot under pressure will it cure or should I make tops for my molds?
 
Hey Drew! Welcome back :wave:

Couple of things on acrylic...

1) Stay away from the HF pressure pot...it's just plain dangerous. I know several guys that have had the lids rip off under pressure. Devebliss or Craftsman would be better choices.
2) PR doesn't need pressure or vacuum. It air dry's just fine...Ask Mack or Les.
3) Michaels...the craft store is a good place...$22.50 a quart here. Watch the Sundays sales ads for a sale...they didn't have one this week :(
4) A guys on Penturners.org sells Resin saver molds and they are the best!! A little spendy, IMHO, but he made me a Cigar and Jr Gent in one so it helped.

Several guys here are much better at resin than me so wait for more advice!:thumb:
 
Pressure

I've read a lot about using pressure versus not. Seems if you are stabilizing wood the pressure is better but no pressure works fine if you just making a resin blank, or so I'm told.

I'll check into different pots, thanks for the tip. Hard to beat the $79 dollar price of the HF pot though.

If not PR, what other options do I have to remain cost effective?

I noticed Menards had fiberglass resin for 10 bucks a quart. Is that the same stuff? It came with activator and all. Thats 40 bucks a gallon and the cheapest I've been able to find on-line is about 48 a gallon + shipping.

I've been trying to build a good plan of action in my head on where to start and how to proceed. So if anyone has any input here are the questions I have:
1) What agent do I use (epoxy, polyester, acrylic ?)
2) Is pressure the best way to make sure this stuff gets into all the voids of a burly or spalted, punky piece?
3) What is the best way to build the pot (adapt, build, purchase etc)
4) How do I add colors? I would want clear resin mostly, but color would be nice down the road.

Thanks in advance guys!
 
Drew, I don't cast anything.
But I do stabilize. I have chosen to use vacuum only.
I am certainly no scientist but I do harken back to my high school physics classes. We were taught that nature hates a vacuum and will fill it with something.
Based on that, I concluded that removing air and moisture from the wood cells with a vacuum will result in the acrylic solution replacing the resulting void. Seems logical to me.
OTOH, I don't see it as logical trying to force solution, with pressure, into cells that are already occupied with moisture and air.
So far my results have been completely satisfactory.
I'll concede this is a hotly debated subject on one of the penturning forums and there are those who do not agree with my approach.
 
I don't exactly cast resin, but I vacuum cast gold and silver and bronze. I also make wax patterns and rtv rubber molds, which are similar processes. Based on what I do know, I would favor vacuum. It will extract any bubbles in the resin the same as Frank suggested it removes air and water from wood. It's also relatively safe, as the most "pressure" you can create with a vacuum is 1 atmosphere, about 14 psi. The use of vacuum could be applied after the material (resin) is mixed and poured into a mold or container. The material volume might increase when full vacuum is achieved due to expanding air bubbles. It actually will look like it is boiling momentarily till the air is removed. My system has a guage that reads inches of mercury and the boiling ocurrs when the guage reads over 28" hg, then it settles back down. After the materials settles you release the vacuum and as atmospheric pressure returns it compresses the material naturally. The same process is used to repair cracked windshields with resins, by the way.
 
I've done quite a few and complex castings out of poliester resin, urethane resin and others, never used vacuum nor pressure, basically it is a matter of pouring the mix making a very thin trickle, that makes all the bubbles dissapear.

A well made mold with proper air exhausts in key places prevents air bubbles getting trapped on it.

If your intention is getting a blank for turning you shouldn't have any problem.
 
In the Library on the IAP forum there is a tutorial on making a vacuum/pressure pot. One pot does both. I'm slowly making a vacuum/pressure pot based on it. Mine is only going to be a pressure pot at first and I will add vacuum as I slowly buy fittings. I priced the fittings and it was twice what I paid for my slightly used Devilbiss pot!

Toni is correct, you can make blanks without pressure/vacuum but I think is you want to cast things in the blank you may need it. Kind of force the bubbles out of or from under thing. I guess a jewelry cleaner helps also. It should be fun to play around with.

If you are not in a great hurry, watch Craigslist for pots. It took a few months but I got a nice Devilbiss with hoses and spray gun for $75. It had been used one time. I think I can pretty easily sell the hoses and gun for $50 or more. The one I found was 230 miles away but in the city my daughter lives in so a good excuse to visit my daughter.
 
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Drew,

I do a lot of casting. Mostly bigger stuff (not many pen blanks but vases etc.) and I have used the "Dangerous Harbor Freight Pots" for years. I have two of them. Remember Paul Harvey? There is always "The Rest Of The Story". All pressure pots have the ability to be dangerous IMHO when used at the pressures needed for proper casting. No one should get a false sense of security about any pot that they use. I am very cautious when casting as I exceed recommended levels of pressure on the pots by a good margin. I don't recommend anyone else use my methods. I do what I need to do to get my desired results and I am willing to take the risk. I have a very high rate of success with my castings.

One of my good friends is probably one of the most prolific pen blank casters in the country and he literally cast hundreds of gallons of resin every year. He has 10 Harbor Freight pots that he uses daily.

Pressure or vacuum really depends on the material. With PR vacuum will work fine. Urethane resins such as Alumalite needs pressure because it starts to set anywhere from 90 seconds to as long as 7 minutes depending on which urethane resin it is and the weather conditions. If you want to limit your chance of bubbles pressure it needed.

Good luck in your endeavor and be vary careful. Casting can be fun and dangerous both for you and your pocket book.

Alan

PS one of my pots is set up for vacuum or pressure. Just remember the more fittings on a pot the more sources for leaks on that pot.
 
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In the Library on the IAP forum there is a tutorial on making a vacuum/pressure pot. One pot does both. I'm slowly making a vacuum/pressure pot based on it. Mine is only going to be a pressure pot at first and I will add vacuum as I slowly buy fittings. I priced the fittings and it was twice what I paid for my slightly used Devilbiss pot!

Toni is correct, you can make blanks without pressure/vacuum but I think is you want to cast things in the blank you may need it. Kind of force the bubbles out of or from under thing. I guess a jewelry cleaner helps also. It should be fun to play around with.

If you are not in a great hurry, watch Craigslist for pots. It took a few months but I got a nice Devilbiss with hoses and spray gun for $75. It had been used one time. I think I can pretty easily sell the hoses and gun for $50 or more. The one I found was 230 miles away but in the city my daughter lives in so a good excuse to visit my daughter.

Paul, you said: "Mine is only going to be a pressure pot at first and I will add vacuum as I slowly buy fittings. I priced the fittings and it was twice what I paid for my slightly used Devilbiss pot!"

I have seen statements like that at IAP a number of times and it confuses me. Of course, I am easy to confuse, so take that into consideration. ;)
Now, my fittings, one, count them ;) also cost more than I paid for my pot. My pot was free. Courtesy of Jay.
What 'fittings' are you going to put on the pot? I know, at IAP, I have seen pics of pots with fittings and hoses that would rival a nuclear reactor. I have never understood why all that is needed.
Following my adherence to the KISS principal, I put a hose on the pot, attached the other end to the vac pump and pump away. Wasso complicated? :dunno:

Edit: BTW if I want pressure I'll put the hose from the pump onto the 'out' connection. Still just a single 'fitting'.
 

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I generally get my resin in gallons from www.uscomposites.com The cost is
$34.50 per gallon of polyester resin Silmar 41, plus shipping and handling. that is a way better price than buying by the quart. I am probably going to order a 5 gallon pail next time and that is $140.50 plus a $20 hazardous material fee plus shipping and handling. I think it works out to be $10 cheaper over all.

I have used alumilite @ $160 for 2 gallons. I did pick this up from the supplier because it is about 1-1/2 hours from my house and a friend was going down that way. I use this for casting over wormy wood hornet nests and that sort of thing. You will want to get the Crystal clear resin because this will take a better polish than the water clear.
 
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