Pressure Pots for PR Casting

[Dean Thomas]

[quote=Anthony Welch;1005971]Here's the cheapest I know of http://http://search.harborfreight.com/cpisearch/web/search.do?keyword=pressure+pot&Submit=Go[/quote (http://http//search.harborfreight.com/cpisearch/web/search.do?keyword=pressure+pot&Submit=Go[/quote)]
Just so I don't hijack the other thread.

This is a pretty interesting topic to me, but I have NO idea how the pressure pot would work. Can we get some instruction here??

How much pressure is required to pressurize a small slab of PR?

How does one keep the pressure in the pot?

What else do we need to know before we try this kind of fun stuff?

[Rusty Smith]

Dean there is an entire section on the International Association of Penturners site on casting. There are several tutorials on the pressure pot construction and it's use as well. Start here: http://www.penturners.org/forum/forumdisplay.php?f=43

Are you a member it the KC Woodturners Asso?

[Dean Thomas]

Yup, I am a member of two of the three clubs in the KC area and I occasionally visit the third.

Appreciate the heads up on the other site. Tomorrow's research topic. :)

[Rusty Smith]

I've been wanting to make it over to KC to some of their club meetings. I've been going all over the country for training in addition to just moving so I've not been able to make it over yet. Next week I am in Atlanta for a week, two weeks later I go to Dallas then to Chicago the week after that. WHEW!!! I'll be glad when it is over. I guess I souldn't complain, at least I have a good paying job and so many places are cutting all training.

Hopefully we can meet when I get a chance to get over to KC.

Rusty

[John Grabowski]

Dean, I hope that you have already found what you are looking for at IAP. Here are some things that I can help with about pressure pots. First of all, they are not cheap to set up.

The main thing that pressure does for your pen blanks is drive the air bubbles out. Less voids means prettier pens. This could also be done by just vibrating the bubbles out.

Pressure is really needed when you are going to be impregnating something into the PR.

If that is of interest to you, then build a pressure pot. If you use teflon tape when connecting all the fittings, pressure remains in the pot.

If you have more questions, feel free to pm me.

John G.

[John Terefenko]

John

I watched your videos and by the way we wait in ernst for the finish. But on your pot do you use both vacuum and pressure??? Can you post a photo of your pot.???? I am right now getting parts to put together one with both vacuum and pressure. Thanks.

I feel I would need the vacuum to cast some pine cone pens and bottle stoppers. I do not think that pressure would force the resin in all the nooks and crannies. I figured I would vacuum for a short time and then pressurise them.

[Chip Sutherland]

and found this conversion for both pressure and vacuum

http://www.penturners.org/forum/showthread.php?t=1488

The link comes up slow for me so I downloaded it. It's well written. There's a wealth of info on the site, too. I especially like Curtis O Seebeck's info on salvaging blanks:

http://builtbydoc.com/WorthlessWoodBlanks.pdf

When I saw the prickly pear cactus blanks that Curtis sells (www.turntex.com (http://www.turntex.com)), I understood the reason for a pressure and a vacuum pot in one. I've got too many projects for 2009 but I'd like to make the PV pot because I've got other non-pen turnings that need this technology.

[Alan Trout]

I do a bit of casting and have a HF pressure pot set up for either pressure or Vacuum. Total cost about $100 with all fittings and gauges.

I cast mostly in Alumilite and pretty much a pressure pot is a necessity for it. For PR it may not be but I have not messed with it much.

Good Luck

Alan

[David Walser]

...
I cast mostly in Alumilite and pretty much a pressure pot is a necessity for it. ...
Alan

Alan, why do you prefer using Alumilite?

[Alan Trout]

There are some advantages with Alumilite. It is thinner so it is better for casting in rotted wormy wood blanks and other mixed media castings because is flows better It can even stabalize soft woods particularly the White and RC3 Alumilite. But with that being said because it sets so fast you need to be fast and need to use a pressure pot. Also all materials need to be dry or it will react and foam. Alumilite is harder then PR and drills much better and in my opinion turns better. It turns more like dry wood than plastic. I do think PR takes a better polish then Alumilite but when using it for mixed media castings a finish such as CA/BLO finish should be applied and is a non factor. If I was just doing 100% resin blank I might consider using PR. Also there is almost no odor associated with Alumilite especially compared to PR. This can be a big factor for people casting in there basements in colder climents where you do not have good ventilation.

Casting is not for everyone and can be tedious and frustrating when working on an idea. Many times you can spend many hours on an idea and either it does not look as good as you thought it might or it just does not work and you just wasted $20 plus dollars of materials on a bad idea.

I have not had much time to cast in the last 3 or 4 month's but hope to get working on some ideas that I have wanted to try for a while.

These are just my opinions which, if you go over to IAP you will find page after page of opinions on which is better.

Good Luck

Alan