Pressure Casting PR

[its_virgil]

Many of yuou have been asking and seem to be interested in the PR casting that I have been doning. Three of us, Serge, Jay Pickens and I, have been experimenting with casting PR in pressurized paint pots. So, here are some of the things these "3 Amigos" have discovered...or sorry Serge, the "Three Mates"

(1) I am down to casting at 40 psi and I think Jay has dropped the pressure down to 30 psi

(2) I have done both clear casting of snake skins and colored castings and as I turn these pieces of PR I have not encountered any bubbles or voids inside the blanks. That is one of the sweetest things I like about the pressure casting. I hated turning a piece of nice colored resin or a snake skin and get almost finished and turn into a bubble. Some can be repaired and some can't. NO MORE BUBBLES!

(3) I have made some shelves to go inside the post to better utilize the space so multiple molds can be cast at once. I also have a top shelf, close to the top of the pot and nothing is on this shelp, but it is used to deflect the air so air rushing in does not disturb the resin, especially in the multi colored casting. Don't know if it is needed, but I use it. I can just visualize a 1/4 inch stream of air at 120 psi blowing a mold full of PR all over the inside of the pot and contaminating the other molds.

(4) As soon as the PR has jelled, the pressure can be released and another casting caan be made. Once it has set the bubbles are trapped in their small state for all of eternity

(5) On clear casting, as in the snake skins, the PR is coming out crystal clear. It was clear prior to pressure casting, but I really think the pressure casting has made it even more clear. Any amount of air in the mix causes some reduction in clearness(or so it would seem to me...I am no chemist nor physicist), but the pressure is eleminating the air and the skins show up better than ever.

(6) Making the first cast using Jay's method of supporting the skinned tubes proved a disaster. Not only does the pressure squeeze the air bubbles to an invisible state, but it also pushed the resin into the tubes between the dowel and the tube. Having metal weights in the tubes to keep them from floating and having the tubes fill with resing...well it was a disaster...But my solution was to use corks...regular corks...Pushed into the tube ends as far as I could...one drop of CA on the corks exposed end and stick a 3/4" square disk to the cork to hold it off the mold bottom. (Read Jay's article on the home page and you will know what I'm talking about) Not a drop of resin in the tubes. The first two casts were done with slimlines. Then I did some barons, gents, sierras and the results were not as successful. The gents filled completely. Maybe I didn't push the corks in far and tight enougng...One baron tube filled and one sierra tube filled. I think the problem was the cork not pushed in far enough. Another cast is coming and I'll have more info on this later. It will get solved.

(7) Cork sizes I've used so far have been #00, #0, #1, #2, #3, and #4. I didn't know corks came in sizes either. The first ones I bought came from Lowes at 34 cents each. I just purchased corks from
http://www.sunburstbottle.com/s.nl/sc.13/category.39/.f and they were 6 to 9 cents each. The corks are not reuseable.

This seem to answer the questions that have been asked of me so far. If I think of any more bits of info I will add to this list. A comprehensive article is in the works on PR casting and snake skin casting. Look for it soon and news-stands nearest you!

Do a good turn daily!
Don

 

[Scott]

Hi Don,

This is very cool! I am glad you and Jay and Serge are working on this! Even after all this time, I still learn something new most every time I visit here! Thanks for sharing!

Scott.

 

[its_virgil]

On thing I just remembered. Serge was using wooden cones he turned and used the yellow teflon tape use by plumbers for gas piping to seal the wooden cone inside the brass tube. Maybe Serge can report on how that worked for him...any news from down under?
Do a good turn daily!
Don

Originally posted by its_virgil
<br />Many of yuou have been asking and seem to be interested in the PR casting that I have been doning. Three of us, Serge, Jay Pickens and I, have been experimenting with casting PR in pressurized paint pots. So, here are some of the things these "3 Amigos" have discovered...or sorry Serge, the "Three Mates"[]

(1) I am down to casting at 40 psi and I think Jay has dropped the pressure down to 30 psi

(2) I have done both clear casting of snake skins and colored castings and as I turn these pieces of PR I have not encountered any bubbles or voids inside the blanks. That is one of the sweetest things I like about the pressure casting. I hated turning a piece of nice colored resin or a snake skin and get almost finished and turn into a bubble. Some can be repaired and some can't. NO MORE BUBBLES!

(3) I have made some shelves to go inside the post to better utilize the space so multiple molds can be cast at once. I also have a top shelf, close to the top of the pot and nothing is on this shelp, but it is used to deflect the air so air rushing in does not disturb the resin, especially in the multi colored casting. Don't know if it is needed, but I use it. I can just visualize a 1/4 inch stream of air at 120 psi blowing a mold full of PR all over the inside of the pot and contaminating the other molds.

(4) As soon as the PR has jelled, the pressure can be released and another casting caan be made. Once it has set the bubbles are trapped in their small state for all of eternity []

(5) On clear casting, as in the snake skins, the PR is coming out crystal clear. It was clear prior to pressure casting, but I really think the pressure casting has made it even more clear. Any amount of air in the mix causes some reduction in clearness(or so it would seem to me...I am no chemist nor physicist), but the pressure is eleminating the air and the skins show up better than ever.

(6) Making the first cast using Jay's method of supporting the skinned tubes proved a disaster. Not only does the pressure squeeze the air bubbles to an invisible state, but it also pushed the resin into the tubes between the dowel and the tube. Having metal weights in the tubes to keep them from floating and having the tubes fill with resing...well it was a disaster...But my solution was to use corks...regular corks...Pushed into the tube ends as far as I could...one drop of CA on the corks exposed end and stick a 3/4" square disk to the cork to hold it off the mold bottom. (Read Jay's article on the home page and you will know what I'm talking about) Not a drop of resin in the tubes. The first two casts were done with slimlines. Then I did some barons, gents, sierras and the results were not as successful. The gents filled completely. Maybe I didn't push the corks in far and tight enougng...One baron tube filled and one sierra tube filled. I think the problem was the cork not pushed in far enough. Another cast is coming and I'll have more info on this later. It will get solved.

(7) Cork sizes I've used so far have been #00, #0, #1, #2, #3, and #4. I didn't know corks came in sizes either. The first ones I bought came from Lowes at 34 cents each. I just purchased corks from
http://www.sunburstbottle.com/s.nl/sc.13/category.39/.f and they were 6 to 9 cents each. The corks are not reuseable.

This seem to answer the questions that have been asked of me so far. If I think of any more bits of info I will add to this list. A comprehensive article is in the works on PR casting and snake skin casting. Look for it soon and news-stands nearest you!

Do a good turn daily!
Don

 

[Darley]

Originally posted by its_virgil
<br />On thing I just remembered. Serge was using wooden cones he turned and used the yellow teflon tape use by plumbers for gas piping to seal the wooden cone inside the brass tube. Maybe Serge can report on how that worked for him...any news from down under?
Do a good turn daily!
Don

Originally posted by its_virgil
<br />Many of yuou have been asking and seem to be interested in the PR casting that I have been doning. Three of us, Serge, Jay Pickens and I, have been experimenting with casting PR in pressurized paint pots. So, here are some of the things these "3 Amigos" have discovered...or sorry Serge, the "Three Mates"[]

(1) I am down to casting at 40 psi and I think Jay has dropped the pressure down to 30 psi

(2) I have done both clear casting of snake skins and colored castings and as I turn these pieces of PR I have not encountered any bubbles or voids inside the blanks. That is one of the sweetest things I like about the pressure casting. I hated turning a piece of nice colored resin or a snake skin and get almost finished and turn into a bubble. Some can be repaired and some can't. NO MORE BUBBLES!

(3) I have made some shelves to go inside the post to better utilize the space so multiple molds can be cast at once. I also have a top shelf, close to the top of the pot and nothing is on this shelp, but it is used to deflect the air so air rushing in does not disturb the resin, especially in the multi colored casting. Don't know if it is needed, but I use it. I can just visualize a 1/4 inch stream of air at 120 psi blowing a mold full of PR all over the inside of the pot and contaminating the other molds.

(4) As soon as the PR has jelled, the pressure can be released and another casting caan be made. Once it has set the bubbles are trapped in their small state for all of eternity []

(5) On clear casting, as in the snake skins, the PR is coming out crystal clear. It was clear prior to pressure casting, but I really think the pressure casting has made it even more clear. Any amount of air in the mix causes some reduction in clearness(or so it would seem to me...I am no chemist nor physicist), but the pressure is eleminating the air and the skins show up better than ever.

(6) Making the first cast using Jay's method of supporting the skinned tubes proved a disaster. Not only does the pressure squeeze the air bubbles to an invisible state, but it also pushed the resin into the tubes between the dowel and the tube. Having metal weights in the tubes to keep them from floating and having the tubes fill with resing...well it was a disaster...But my solution was to use corks...regular corks...Pushed into the tube ends as far as I could...one drop of CA on the corks exposed end and stick a 3/4" square disk to the cork to hold it off the mold bottom. (Read Jay's article on the home page and you will know what I'm talking about) Not a drop of resin in the tubes. The first two casts were done with slimlines. Then I did some barons, gents, sierras and the results were not as successful. The gents filled completely. Maybe I didn't push the corks in far and tight enougng...One baron tube filled and one sierra tube filled. I think the problem was the cork not pushed in far enough. Another cast is coming and I'll have more info on this later. It will get solved.

(7) Cork sizes I've used so far have been #00, #0, #1, #2, #3, and #4. I didn't know corks came in sizes either. The first ones I bought came from Lowes at 34 cents each. I just purchased corks from
http://www.sunburstbottle.com/s.nl/sc.13/category.39/.f and they were 6 to 9 cents each. The corks are not reuseable.

This seem to answer the questions that have been asked of me so far. If I think of any more bits of info I will add to this list. A comprehensive article is in the works on PR casting and snake skin casting. Look for it soon and news-stands nearest you!

Do a good turn daily!
Don

Don your problem is the cork quality you use IMHO you got cork and cork, I explain cork is a bark and bark are porous good cork will be 1 piece, medium and bad cork will be reconstitued with the crushed left over of the cork bark when doing ( or punching ) cork, don't forget wine is a living material and need air to age and getting better so cork is a great way to do this, when you plug your tubes with cork tube size matte I think because you give more lea way to the PR to go through the cork when under pressure may be you should seal the cork with CA first before pluging into the tube ( CA as to be dry of course ) my little wooden plug work well for me 40PSI is plenty and I leave my casting 6 mintues, air from the compressor accelerate the gelling process of the PR I think, you're right about a little sleving above the casting I didn't do it last December on my first casting and I have my little pot full of PR [] didn't do any PR for 2 weeks now waiting for the sapre tubes to come

 

[TomServo]

Why not use rubber corks?

 

[Skye]

I think because they cut through the corks then push them throught the tubes. Rubber may be tougher to cut and push, who knows the cutting process may even stain the PR. Just my guesses though, never done a casting.

 

[its_virgil]

PR sticks to almost everything....including rubber. The stoppers are destroyed in cutting off the blanks from the slab. Rubber stoppers = 50 cents(for the larger sizes for gents etc) and cork stoppers = 6 cents. So using 4 rubber stoppers per pen adds $2 to the cost of each pen. OUCH! It would be great if they were salvageable.
Do a good turn daily!
Don

Originally posted by TomServo
<br />Why not use rubber corks?

 

[its_virgil]

Serge,
You may be correct. The corks are whole, one piece corks and I tried to pick out corks with no inclusions on the surface. I still reallyu think that they leaked because my sledge hammer is too small[]

I have more skins glued on some gent tubes and I'll try again this evening. I will make sure the large sledge is working. More later. I think I will use some CA as a seal.
do a good turn daily!
Don

Don your problem is the cork quality you use IMHO you got cork and cork, I explain cork is a bark and bark are porous good cork will be 1 piece, medium and bad cork will be reconstitued with the crushed left over of the cork bark when doing

 

[JimGo]

Don, have you tried coating them with petroleum jelly or wrapping them in plastic wrap?

 

[kgwaugh]

Serge and all...

I have not gone looking for them, but there are tapered plug cutters available for woodworkers, designed for plugging screw holes. Now, IF there is an appropriate size available, it would be very easy to turn out lots of small tapered plugs quickly---you just set up in a drill press, drill into your material of choice, and then slab them out with (preferably) a bandsaw. I would start looking at Rockler, Woodcraft, Lie-Nielson, and that sort of supply house.


Good Luck, I have one of the sale pressure pots on its way, and "one of these days.....

Gene
Elgin, Illinois USA

 

[its_virgil]

No not yet. But I'm making a list of all the suggeastions you guys are offering. I'll bet one of them will work. Thanks and I'll announce who hmade the winning suggestion when I find it. Thanks for the help and suggestions.
do a good turn daily!
Don

Originally posted by JimGo
<br />Don, have you tried coating them with petroleum jelly or wrapping them in plastic wrap?

 

[JimGo]

Something like this Gene?
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=33571

 

[vbatwork]

Those tapered cutters should work Jim. I remembered using some Veritas tapered plug cutters that worked really well for filling countersunk screw holes. I see HF has a whole set available for the price of one Veritas cutter at Woodcraft. *sigh*

http://www.woodcraft.com/family.aspx?familyid=775&refcode=05IN02NL

 

[pssherman]

Don,
You could try using the rubber stoppers if you coat them with vaseline or anything else that the PR would not stick to. Then, cut them out right at the largest part of the stopper, so that you don't destroy them, and pry them out of the mold. After which you can trim the blanks to their proper length. This may be a bit more work, but it should solve the leakage problem and allow you to reuse the rubber stoppers.

Paul in AR

 

[Mudder]

Don,

Thank you for such a clear and concise write up. I had some gift cards to use up so I bought a pot from Sears and soon I’ll be ordering a slew of corks (thanks to you) fairly cheaply and hope to be in the pressure casting business in the next couple of weeks.

I did have a thought that may or not help as I have not tried it. What do you suppose would happen if you coated the corks with rubber cement to kind of “seal†them? Seems to me if the cork is coated with something to “seal†it, that should solve any problems of PR absorption by the cork? What do you think?

 

[its_virgil]

Mudder,
Yor're welcome. There is a much better writeup in the mill with pictures and everything. It will cover casting snake skins and doing various color techniques.

The PR is not getting in the corks itself and then inside the tubes. None of the corks I've sawed through were saturated with PR. They were all dry as a bone. That is not the problem. The problem is that some of the larger tubes had resin inside the tubes ... the tubes were filled with resin...I am sure it leaked in between the cork surface and the inside surface of the tube, not actually through the cork itself. I really do think I should have pushed the larger corks in the tubes further. None of the slimlines have leaked at all. No cigar tubes have leaked. Baron, cigar, and sierra tubes are close to the same size...some(baron and sierra) leaked and some did not. I really do think it is my fault for not pushing in the corks farther. I have some more tubes ready to be cast and I will be sure I seat the corks firmly and give it one more try before I start trying to seal the cork/tube connection.
Do a good turn daily!
Don


"

Originally posted by Mudder
<br />Don,

Thank you for such a clear and concise write up. I had some gift cards to use up so I bought a pot from Sears and soon I’ll be ordering a slew of corks (thanks to you) fairly cheaply and hope to be in the pressure casting business in the next couple of weeks.

I did have a thought that may or not help as I have not tried it. What do you suppose would happen if you coated the corks with rubber cement to kind of “seal†them? Seems to me if the cork is coated with something to “seal†it, that should solve any problems of PR absorption by the cork? What do you think?

 

[kgwaugh]

Originally posted by JimGo
<br />Something like this Gene?
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=33571

yessir

 

[JimGo]

Don,
Another idea is to turn a few scrap pieces into spacers for inside the tubes, and to seal the ends with base plate wax. Of course, this doesn't help suspend it, but it might meet your other requirements.

 

[its_virgil]

I had base plate wax melt a couple of times from the heat generated in the curing and have not tried using it again. I wonder if they tend to float because of the air in the tubes or because of the wooden "feet" I'm using to support the tubes. Would the wood inside make them want to float more, or dispell the air and solve the floating problem. I may check that out too. If wood inside the tubes works then if I did have some leakage, them it would drill out.
Do a good turn daily!
Don

Originally posted by JimGo
<br />Don,
Another idea is to turn a few scrap pieces into spacers for inside the tubes, and to seal the ends with base plate wax. Of course, this doesn't help suspend it, but it might meet your other requirements.

 

[JimGo]

If you use a dense piece of wood, or even better a bolt or other piece of rod stock, you might be able to both weigh down the piece and reduce the amount of PR that can get into the tubes. The rod could probably be knocked out, leaving only whatever residual PR is in the tube. Hmmm...I may have to try this!

 

[JimGo]

Actually, now that I'm remembering it (it's been at least six months since I've done any casting) an idea I had was to use nuts and washers on some threaded rod. If you coat the washer with a little petrolium jelly, paste wax, etc., it should come free pretty easily.

EDIT:
OK, here's what I had (kind of) envisioned. Remember that I do most of my casting in the ice cube trays. I like them because I can control the depth. In this set-up, the waste blocks are turned to JUST fit inside the ice cube tray. They act to give a little clearance from the bottom of the mold, and to help keep things centered. When the waste blocks are removed (assume they are coated with wax to help them slip into the mold, and to keep the PR off of them), you may have PR against the nut at the bottom, but if that's wax coated too, it shouldn't be hard to break it free. That only leaves the "washers" on the ends. If they are made of a sacrificial material (e.g. waste wood), or if they're coated with wax, they can either be turned/drilled out or possibly even pulled out.

Although this is designed for my style of casting, it should also work (or can be easily adapted to work) with the horizontal castings.

What do you think, Don (or anyone else)?

<br />

 

[Darley]

So Don if I understant correctly PR in your tubes is because you have a gap between the corck and the ID tube. am I correct? to weight my blank I put some fishing sinkers in the tube, for your cork ( I assume you cut them by hand so they are not perfectly round ) try to use the teflon tape to make a tight fit, I don't think rubbet stopper will give a better job but sure like you say will rise the price of the pen $ 2.00 more,

Jim your idea isn't bad but then you have to be carreful when tightne up the nut not to crush the tube as this will act as a vise.

Edit
The 3 Gringos ( or Mates ) and they plug saga................. to be continued[]

 

[GaWoodworker]

I have had good success with blocking the tubes with Modelling clay. I pressure cast at 50 psi and have not had any resin in the tubes. I also have metal as weight inside my tubes, but the clay is easily pushed out with the metal after the cast is complete.

 

[Darley]

Originally posted by GaWoodworker
<br />I have had good success with blocking the tubes with Modelling clay. I pressure cast at 50 psi and have not had any resin in the tubes. I also have metal as weight inside my tubes, but the clay is easily pushed out with the metal after the cast is complete.

I though about the modeling clay but got a little problem, If I buy the fresh clay 500grs ( just a little over the pound ) and I don't use the lot it will be wasted because the clay dry at air, look that way 1 pound of clay seal a lot of tubes, the idea behin the " sealing tubes question " is to have an easy way to do and is not heavy to the pocket, what I would say minimizing cost to produce a good product.

 

[Charles]

Hi folks, I have done some PR casting in trays but would like to obtain the pressure pot. What brand/type are you using and where can I find them. Thanks for the help.

 

[brokenbit]

Just got 1 at HF 79.99 Pressure to 80 psi

Bernie

 

[its_virgil]

I'm down to 40psi and one of my amigos is down to 30psi to eleminate air bubbles. I think I will settle in on 40psi.
Do a goof tuen daily!
Don

Originally posted by brokenbit
<br />Just got 1 at HF 79.99 Pressure to 80 psi

Bernie

 

[alamocdc]

Originally posted by JimGo
<br />OK, here's what I had (kind of) envisioned. Remember that I do most of my casting in the ice cube trays. I like them because I can control the depth. In this set-up, the waste blocks are turned to JUST fit inside the ice cube tray. They act to give a little clearance from the bottom of the mold, and to help keep things centered. When the waste blocks are removed (assume they are coated with wax to help them slip into the mold, and to keep the PR off of them), you may have PR against the nut at the bottom, but if that's wax coated too, it shouldn't be hard to break it free. That only leaves the "washers" on the ends. If they are made of a sacrificial material (e.g. waste wood), or if they're coated with wax, they can either be turned/drilled out or possibly even pulled out.

<br />

This is basically what I used when I cast my giraffe print in clear PR. It worked well. A few well placed band saw cuts and everything popped free. Gave all of the metal a pretty good coat of petroleum jelly. Just be careful not to have so much on the washers that it trnasfers to the tube or material on the tube. Oh, I used carriage bolts instead of all-thread, but same principal otherwise.

 

[its_virgil]

Actually I purchased them online. They are nice corks, whole, not cut from stacked disks. They do have a few voids and I will be careful to use the ones that will not have their voids interfere.
Do a good turn daily!
Don

Originally posted by Darley
<br />So Don if I understant correctly PR in your tubes is because you have a gap between the corck and the ID tube. am I correct? to weight my blank I put some fishing sinkers in the tube, for your cork ( I assume you cut them by hand so they are not perfectly round ) try to use the teflon tape to make a tight fit, I don't think rubbet stopper will give a better job but sure like you say will rise the price of the pen $ 2.00 more,

Jim your idea isn't bad but then you have to be carreful when tightne up the nut not to crush the tube as this will act as a vise.

Edit
The 3 Gringos ( or Mates ) and they plug saga................. to be continued[]

 

[vbatwork]

I like the idea of embedding the tubes in the PR. One less step. Since many of you are experimenting with this, do you find the PR bonds to the tubes as well as glue for later turning?

- John

 

[JimGo]

John,
The problem I run into is that I never know what type of pen I will want to make next, and if I cast a tube into the blank, I'm inherently limiting myself. So, although I started trying to cast the tubes into the blanks, I quickly abandoned that idea. The exception to this is, of course, where casting a skin or the like in the resin; then, since I'm already gluing the skin to the tube, I've basically committed myself.

The two times I tried casting PR directly to the tubes it came out fine, although I did scuff up the tube first.

 

[Joe Melton]

Curing resin under pressure to remove bubbles seems counter-intuitive to me. Obviously, it works, though.
But, I'm wondering why no one is using vacuum instead of pressure. Has someone gone down this road?
Joe

 

[Skye]

Well, because it dosent really remove the bubbles as I understand it. The blank is under 40psi which shrinks down the bubbles by compressing them as well. The bubbles are still there, but they're so small it looks clear.

Just the way I understand it.

 

[its_virgil]

After reaearching resin casting on some casting forums, I found out that some resins are cast in a vacuum and others are cast under pressure. Polyester resin, which is what I cast around snake skins, is one of the resins that is cast using pressure. Others have tried vacuum and maybe they will offer some information. I've not seen much info on vacuum casting. There was some at one time, but its been awhile since I've seen any posts on vacuum casting. polyurathand resin is cast in a vacuum and maybe eposy resin. Besides, I already had a compressor.

Doesn't matter to me whether they are shrunk down too small to see, whether they dissappear, or hide behind the trees....I'm just gland they are gone or whatever they are. My castings are soooo much more clear.

do a good turn daily!
Don

Originally posted by Joe Melton
<br />Curing resin under pressure to remove bubbles seems counter-intuitive to me. Obviously, it works, though.
But, I'm wondering why no one is using vacuum instead of pressure. Has someone gone down this road?
Joe

 

[Darley]

Hey Don we should contact HF to have contract signed for the sale of every paint pot[][] will pay the PR, tube and skin[]

 

[its_virgil]

Yea, we need a referal fee. I was wondering the other day how many paint pots have been sold by HF since this all started. I wonder how many of us have bought the paint pots.
do a good turn daily!
Don

Originally posted by Darley
<br />
Hey Don we should contact HF to have contract signed for the sale of every paint pot[][] will pay the PR, tube and skin[]

 

[kgwaugh]

I ordered one about a week ago on sale (half price) and got a postcard yesterday saying it was on backorder. Guess we messed up their projections!

 

[Phil Joines]

MSC sells nylon washers for about $5 per 100. I'd think they'd be nonstick. The local ACE hardware carries a fer but not in the size ranges.

 

[Skye]

If not, cut up a <b>Silpat</b>.

 

[ccarse]

Originally posted by Skye
<br />If not, cut up a <b>Silpat</b>.

Talk about expensive!