casting without pressure/vacuum

[ahoiberg]

i'm sure this topic has been beat into the ground and i'm not looking for people to say that you will end up with bubbles as i'm sure to at some point. but i'm looking for those of you who don't use a pressure pot/vacuum to see if you have any tips for doing it the non-pressure way? just hope and pray??

thanks. maybe once i try this way, i'll know why i should use the pot!

 

[Narwhale]

Believe there is a lot of us that cast pen blanks without pressure.
I cast 1/2" and 3/4" pvc pipe molds with colored polyester resin without resorting to pressure or suction. I mix the color in first, let set while I mix the other colors up, then add hardener and mix. Let sit another few minutes and then start pouring slowly directly into molds.
Entrained air and bubbles are almost nonexistant.
Don't think this would work if I was casting in a mold with catus, sponge, or even the brillo pad.
Rich S.

 

[ElMostro]

Use Allumilite! It can be done. I use a pressure pot but have tested not using the pot. The key is to carefully mix the mix (mix the mix[]) so that you do not introduce air bubbles. Then carefully pour into the mold as close to the mold as possible again to avoid introducing bubbles. When you turn the blank IF you have any voids use CA to correct them. Eugene

 

[ed4copies]

Casting things in the molds will create voids. Makes turning a challenge.

Different times to "set" for different color agents also creates challenges.

But, nice normal "pour a blank" can be done without pressure or vacuum.

Try it, it's pretty simple.

 

[alamocdc]

I've yet to pressure or vacuum cast, but I have done a fair amount of casting and the only time I get bubbles is when I use too much catalyst. My casts take from 2 ot 4 days to fully cure and don't seem to be as brittle as others I've turned.

 

[RONB]

Originally posted by ahoiberg
<br />i'm sure this topic has been beat into the ground and i'm not looking for people to say that you will end up with bubbles as i'm sure to at some point. but i'm looking for those of you who don't use a pressure pot/vacuum to see if you have any tips for doing it the non-pressure way? just hope and pray?? []

thanks. maybe once i try this way, i'll know why i should use the pot!
[/quote
I did have problems casting snake skins before buying the vacuum pot.
I got a lot of air trapped along side the skins. Coulden't use CA there.It's much improved after vacuum and pressure. Haven't lost one since.

 

[Glass Scratcher]

Originally posted by alamocdc
<br />I've yet to pressure or vacuum cast, but I have done a fair amount of casting and the only time I get bubbles is when I use too much catalyst. My casts take from 2 ot 4 days to fully cure and don't seem to be as brittle as others I've turned.

How much catalyst do you normally use?

 

[alamocdc]

I typically use 4 drops/ounce and IIRC the bottle says to use 7. It should be noted that I have yet (and will not try) to use this method on snakeskins, or any other embedded castings. These I will certainly pressure cast.

 

[its_virgil]

Billy,
I use just 3 drops per ounce, cast in the evening and the blanks are ready to turn the next morning. I am pressure casting and these are snake skins. Hummmmm!
Do a good turn daily!Don

Originally posted by alamocdc
<br />I typically use 4 drops/ounce and IIRC the bottle says to use 7. It should be noted that I have yet (and will not try) to use this method on snakeskins, or any other embedded castings. These I will certainly pressure cast.

 

[its_virgil]

There is an additive called "bubble eater" but I have no first hand knowledge of it.
Do a good turn daily!
Don

Do a

Originally posted by RONB
<br />

Originally posted by ahoiberg
<br />i'm sure this topic has been beat into the ground and i'm not looking for people to say that you will end up with bubbles as i'm sure to at some point. but i'm looking for those of you who don't use a pressure pot/vacuum to see if you have any tips for doing it the non-pressure way? just hope and pray?? []

thanks. maybe once i try this way, i'll know why i should use the pot!
[/quote
I did have problems casting snake skins before buying the vacuum pot.
I got a lot of air trapped along side the skins. Coulden't use CA there.It's much improved after vacuum and pressure. Haven't lost one since.

 

[ed4copies]

I believe Billy in Ohio and Don in Texas have just given more credance to my suspicion that ambient temperature and humidity are contributing factors to the speed with which "setting" occurs. Texas is hotter, generally. And, if I recall correctly, Don's wife has kicked him and his "stinky goo" out of the house - so air conditioning is not a factor!!

[][][][]Right?? Don?????

 

[its_virgil]

Right Ed,
Heat and humidity are definitely factors. Casting in pressure I'm able to run the air through a moisture collector and that helps. My shop has heat and air so when I cast in the summer I turn on the AC mid afternoon, cool down the shop and cast in the late evening. Turn off the AC and leave it all night. They are ready the next morning.

Anthony casts outside...maybe his wife is the one who kicked him out with his sticky PR...maybe she kicked him out for other (golf, cigars) reasons.[][][}][}][B)] The guy who casts the snake blanks for BB does not cast when the temp rises above the lower 90s. He casts early morn and evening.

I've had the skins totally vanish from the tubes. I was casting outsied, hot summer day and still using 6 drops per ounce. I think the silicone rubber molds that gadget is selling helps with two things...heat and PR usage. I use less PR for the same number of tubes than I once did. For exapmle, I cast 4 sets of barons in the 3/4" mold and use only 7 ounces of resin where I once used 12 for the same number of sets. That's close to a 50% savings in resin.

Do a good turn daily!
Don

Originally posted by ed4copies
<br />I believe Billy in Ohio and Don in Texas have just given more credance to my suspicion that ambient temperature and humidity are contributing factors to the speed with which "setting" occurs. Texas is hotter, generally. And, if I recall correctly, Don's wife has kicked him and his "stinky goo" out of the house - so air conditioning is not a factor!!

[][][][]Right?? Don?????