Can I.........???

[jtdesigns]

I just made a pressure pot from a Devilbiss pot I had laying around. Will I be able to use it with Sil 41 and feather blanks.

Jeff

 

[gketell]

yup

 

[PaulDoug]

I think this is a stealth gloat! Snuck in. Shame on you.:biggrin:

 

[jtdesigns]

I think this is a stealth gloat! Snuck in. Shame on you.:biggrin:

Absolutely not (just lucky):biggrin: I would rather use pressure vs. vacuum..don't need to spend money on pump if my air compressor will work. Why do some say vacuum PR and pressure Alumalite?

 

[workinforwood]

Well, with PR there is plenty of time to vaccuum air bubbles away and at the same time, by sucking out air you are able to draw the PR into things like wood better than you would with just pressure.

With Alumilite, there is no time for vacuum, especially this time of year. That stuff flashes off like a rocket ship...mix, pour, pressure fast as you can!

 

[gketell]

Absolutely not (just lucky):biggrin: I would rather use pressure vs. vacuum..don't need to spend money on pump if my air compressor will work. Why do some say vacuum PR and pressure Alumalite?

If you are casting a solid block of color there is no real reason for vacuum. Pressure is enough to "squash" any bubbles in it to invisibility.

You NEVER want to do vacuum only and leave it under vacuum until the material sets. The vacuum will cause the bubbles in the material to expand. Some will pop, some won't. If it hardens still under vacuum them all those expanded bubbles are frozen into your material, nice and rough and "gappy".

If you are casting into something very porous, the best solution is vacuum to pull all the air out of the porous material followed by pressure to shove the casting material into the holes you are trying to fill.

But, as Jeff said, with Alumilite you don't have time to do both so you have to choose either vacuum or pressure. See note above... So it is pressure only.

 

[jtdesigns]

I guess it would make sense to tell you what I'm casting. I have been a fly fisherman for 20 years and have always taken great pride in tying my own flies. I finally reached a point of diminishing returns......after all I haven't fished in two years and I have built up quite an inventory of flies. Anyway, I got real excited when all this talk about feather blanks came up because I have a rather large supply of neck and saddle hackles (feathers) that would look pretty cool (white/black barred grizzly, olive grizzly, etc) so I am in the process of finishing a few blanks to be cast. Using Shane's tutorial, I am concerned about the potential for air bubbles trapped underneath the feathers so I thought I would go ahead and make a pressure/vacuum pot. If I can get away with pressure (I use PR) that would be great since I have a compressor.

 

[gketell]

If you have a compressor you can get a venturi driven vacuum pump for it for less than $10 from Harbor Freight.

http://www.harborfreight.com/air-vacuum-pump-with-r134a-and-r12-connectors-96677.html

Just change the front fittings to something easy to use and you have a perfectly good (if noisy) vacuum pump for casting. That is what I've used for all my vacuum-based casting.