# Need some advice



## larry C

I need some advice, from you pro folks. I've been turning some "pencil bowls" using colored pencils and epoxy to bind them together.

I've been using "System 3" two part epoxy, with a 1 hour set time...it works fine, but is there a way to do this without having bubbles trapped in the final product. I've been especially careful when mixing it to stir very slowly, and that helps, but I'm still having the problem.

I'm wondering if y'all could recommend a way to do this, or recommend a different product...I've been wondering about some of the 2 part "pour on" thick finishes....

Thanks guys..


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## gman2431

Dont know much about this at all but my first guess would involve a pressure pot.


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## larry C

gman2431 said:


> Dont know much about this at all but my first guess would involve a pressure pot.



I was afraid that's what the answer would be.....I don't have one, and at this point in life, not too sure if I want to learn the process.....somebod said something about heat,
but it seems to me that would make it worse...

Thanks for the response...


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## Schroedc

I like Silmar 41, one trick that can help is to warm the resin a bit so it flows easier, cut the catalyst back a ways so it takes longer to set. ( I don't know if you can do that with the West Epoxy) It's what I do to pour the stamp blanks so they don't get bubbles. also- some vibration as it's poured and then after might help. set it on the table saw or router table and just let it run a while.

Reactions: Thank You! 1 | Agree 2


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## larry C

Schroedc said:


> I like Silmar 41, one trick that can help is to warm the resin a bit so it flows easier, cut the catalyst back a ways so it takes longer to set. ( I don't know if you can do that with the West Epoxy) It's what I do to pour the stamp blanks so they don't get bubbles. also- some vibration as it's poured and then after might help. set it on the table saw or router table and just let it run a while.



The West system material is good, and I use quite a lot on other projects. This I've been using has a one hour set time (depending on temperature), I'm going to pour another one
tomorrow, I'll try heating it in a double boiler, then set it on the saw, the vibration trick might be the answer....
Thanks

Reactions: Like 1


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## barry richardson

A trick for bartop, not sure if it would work for this, is to sweep the surface with a torch, the heat expands the bubbles and brings them to the surface... (in the liquid state of course) before it sets up

Reactions: Thank You! 1 | Informative 2


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## rocky1

Ditto on what Colin said up there...

The pressure pot works, but no it's not a cure all either. Personally, I'd like to set mine on a vibration table, but I'm fairly certain the noise from that 5 gallon pot sitting over there rattling and humming would drive me nuts.

Viscosity of the resin definitely impacts your pour, as does delayed set times, (_even with the pressure pot_).

While I would agree warming the resin to reduce viscosity is good in that respect, and Colin is no doubt doing that with success. With the Silmar resin you're able to adjust the catalyst to compensate for that and slow set time in spite of warming the resin. Colin and @norman vandyke have both indicated cutting catalyst back on the Silmar to the point they're talking days to set, not hours. I haven't backed it off that far yet, but I have stretched it to several hours. If you only have an hour set time to deal with on the West System resin, you definitely want to consider how temperature is going to affect your set time, before warming your resin too much.

Reactions: Like 1


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## larry C

rocky1 said:


> Ditto on what Colin said up there...
> 
> The pressure pot works, but no it's not a cure all either. Personally, I'd like to set mine on a vibration table, but I'm fairly certain the noise from that 5 gallon pot sitting over there rattling and humming would drive me nuts.
> 
> Viscosity of the resin definitely impacts your pour, as does delayed set times, (_even with the pressure pot_).
> 
> While I would agree warming the resin to reduce viscosity is good in that respect, and Colin is no doubt doing that with success. With the Silmar resin you're able to adjust the catalyst to compensate for that and slow set time in spite of warming the resin. Colin and @norman vandyke have both indicated cutting catalyst back on the Silmar to the point they're talking days to set, not hours. I haven't backed it off that far yet, but I have stretched it to several hours. If you only have an hour set time to deal with on the West System resin, you definitely want to consider how temperature is going to affect your set time, before warming your resin too much.



I'm almost out of the West System material, where is the best place to buy the Silmar material?


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## rocky1

Cheapest prices I've found... Consider a 2 gallon order. Freight has haz-mat fees involved, and a second gallon only costs $4 - $5 more to ship. My last order freight was $19 and change on one gallon, it was right at $22 - $23 on 2.

http://www.carbonfiberglass.com/Res...-41-Clear-Polyester-Casting-Resin-Gallon.html


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## rocky1

Not sure about the West Systems, but be advised Silmar does have a strong odor of fiberglass resin. Not something you want to pour in the basement of the house. We forgot to warn Norm!

Reactions: Informative 1


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## larry C

That's not a problem


rocky1 said:


> Not sure about the West Systems, but be advised Silmar does have a strong odor of fiberglass resin. Not something you want to pour in the basement of the house. We forgot to warn Norm!



That's not a problem I've got good ventilation.


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## Jerry B

I know several guys @ Segmented Woodturners that do the colored pencils, they all swear by using epoxy, 1 does the vibration, the others use the pressure pot
There's really nothing to learn, make a mold, insert the pencils, pour the epoxy, and use roughly 50 psi until the epoxy sets ...... 
just remember to make the mold larger than desired finish size because when applying the pressure it'll compress the epoxy ......
but you're almost guaranteed to have no air bubbles when done

when I do this making worthless wood blanks & Alumilite, I lose almost 1/4" with a 5x5 mold (mold is 1-1/4" tall so finish pieces are 1" thick after setting up/curing)

Reactions: Informative 1


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## rocky1

I was looking around on the Silmar page Larry, and wandered off into the questions at the bottom of the page. Back early 2015 a gentleman by the name of Chris Osborne, obviously the dealer or a factory rep, began answering questions on that product. There is a lot of very good information found there. Recommendations on catalyst to use varying by volume of pour, temperature, etc. Given your pour is going to be larger than what we typically pour, you might want to read up on some of that information.

Reactions: Informative 1


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## Schroedc

And the thicker your pour on Silmar, the more shrink you can have. When I was pouring bars 16 inches long, by the time they set and cured they'd shrink 3/16 in length.

Reactions: Informative 1


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## larry C

rocky1 said:


> Cheapest prices I've found... Consider a 2 gallon order. Freight has haz-mat fees involved, and a second gallon only costs $4 - $5 more to ship. My last order freight was $19 and change on one gallon, it was right at $22 - $23 on 2.
> 
> http://www.carbonfiberglass.com/Res...-41-Clear-Polyester-Casting-Resin-Gallon.html




Rocky, is this the resin you are talking about? Unless I'm missing something, the specs are that is has a very short pot life, I see that it's a 1:1 mix ratio.
I guess my question is, how much do you decrease the ratio in order to increase the pot life....


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## larry C

larry C said:


> Rocky, is this the resin you are talking about? Unless I'm missing something, the specs are that is has a very short pot life, I see that it's a 1:1 mix ratio.
> I guess my question is, how much do you decrease the ratio in order to increase the pot life....



*Easy-Flo 60 Low-viscosity polyurethane casting resin – 2 Gallons*


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## larry C

@rocky1 , I think I may have answered my own question, this one sounds like what you guys are talking about...

*Silmar 41 Clear Polyester Casting Resin (Gallon)*

Reactions: Agree 1


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## larry C

Schroedc said:


> I like Silmar 41, one trick that can help is to warm the resin a bit so it flows easier, cut the catalyst back a ways so it takes longer to set. ( I don't know if you can do that with the West Epoxy) It's what I do to pour the stamp blanks so they don't get bubbles. also- some vibration as it's poured and then after might help. set it on the table saw or router table and just let it run a while.



Colin, I ordered a couple gallons of Silmar 41, they recommend 5 drops of catalyst/ounce of resin....I'm wondering what the working time (pot time) of the mixture would be 
at, let's say 70 degrees air temp and 60% humidity.....the lady I talked to at the company said they don't recommend using less than 5 drops/ounce.....After reading what you 
guys are saying, I'm thinking that there are variables they don't want to talk about....
I've used a lot of resins before, so this really isn't my first rodeo, but I would like to minimize the problems that may occur the first time I use it.

These pencil holders I've been making are about 4" x 4", but the wall thickness of the resin is only about 5/8" thick. I use a form that is a wood disk on the bottom (that will be the bottom of the holder, with a 2" diameter wood dowel, and a wood disk on top for the rim of the object. The center 2' dowel is a "sacrificial" piece, used only to minimize the amount of resin....

Hopefully all this rambling hasn't confused you too much.....I do appreciate your help.
Thanks,
Larry


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## Schroedc

larry C said:


> Colin, I ordered a couple gallons of Silmar 41, they recommend 5 drops of catalyst/ounce of resin....I'm wondering what the working time (pot time) of the mixture would be
> at, let's say 70 degrees air temp and 60% humidity.....the lady I talked to at the company said they don't recommend using less than 5 drops/ounce.....After reading what you
> guys are saying, I'm thinking that there are variables they don't want to talk about....
> I've used a lot of resins before, so this really isn't my first rodeo, but I would like to minimize the problems that may occur the first time I use it.
> 
> These pencil holders I've been making are about 4" x 4", but the wall thickness of the resin is only about 5/8" thick. I use a form that is a wood disk on the bottom (that will be the bottom of the holder, with a 2" diameter wood dowel, and a wood disk on top for the rim of the object. The center 2' dowel is a "sacrificial" piece, used only to minimize the amount of resin....
> 
> Hopefully all this rambling hasn't confused you too much.....I do appreciate your help.
> Thanks,
> Larry



I'll pull my notes on Sunday abd get you some guidelines to start from. I'm in a play this weekend

Reactions: Thank You! 1 | Great Post 1


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## rocky1

Schroedc said:


> I'll pull my notes on Sunday abd get you some guidelines to start from. I'm in a play this weekend



Good grief man... first you turn pens, then you sell tools, then you cook, then you're the neighborhood mechanic and fix it man repairing the neighbor's transmission, deliveryman, truck driver, now you're on Broadway!




larry C said:


> Colin, I ordered a couple gallons of Silmar 41, they recommend 5 drops of catalyst/ounce of resin....I'm wondering what the working time (pot time) of the mixture would be
> at, let's say 70 degrees air temp and 60% humidity.....the lady I talked to at the company said they don't recommend using less than 5 drops/ounce.....After reading what you
> guys are saying, I'm thinking that there are variables they don't want to talk about....
> I've used a lot of resins before, so this really isn't my first rodeo, but I would like to minimize the problems that may occur the first time I use it.
> 
> These pencil holders I've been making are about 4" x 4", but the wall thickness of the resin is only about 5/8" thick. I use a form that is a wood disk on the bottom (that will be the bottom of the holder, with a 2" diameter wood dowel, and a wood disk on top for the rim of the object. The center 2' dowel is a "sacrificial" piece, used only to minimize the amount of resin....
> 
> Hopefully all this rambling hasn't confused you too much.....I do appreciate your help.
> Thanks,
> Larry




If you've used resins before, Silmar is pretty simple. The "5 drops per ounce" is a good rule to know for smaller batches, but the product typically comes with a little measuring cup for the catalyst. Somewhere in the questions and responses on the webpage he converted that to milliliters, as best I recall. Instructions received with the product from previous supplier indicated a baseline 100:1 ratio on the mix.

1 ounce = 29.57 ml
1 drop = .05 ml

So... 5 drops/1 ounce would be .25 ml/29.57 ml or .0084545 ml. (_roughly 1/100_)
Roughly back to the 100:1 baseline ratio.

While it will vary dependent upon the amount of catalyst used, and Colin has certainly way more experience playing there than I, and notes, just so the suspense doesn't do you in while he's off doing his Burt Reynolds imitation this weekend...

At the stated 100:1 ratio, pouring 1"x 1"x 2 1/4" pen blanks, approximately 35 ml per blank, total of 185 ml resin and roughly 2 ml of catalyst per batch. I was right around 45 minutes in from adding catalyst, before bubbles started suspending in my cast sitting on the table saw, at conditions slightly warmer than what you mention above.

That of course will vary dependent upon size of the pour and rate of exothermic reaction.

Reactions: Thank You! 1 | Informative 1


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## larry C

rocky1 said:


> Good grief man... first you turn pens, then you sell tools, then you cook, then you're the neighborhood mechanic and fix it man repairing the neighbor's transmission, deliveryman, truck driver, now you're on Broadway!
> 
> 
> 
> 
> 
> If you've used resins before, Silmar is pretty simple. The "5 drops per ounce" is a good rule to know for smaller batches, but the product typically comes with a little measuring cup for the catalyst. Somewhere in the questions and responses on the webpage he convertewww.woodturnerscatalog.comd that to milliliters, as best I recall. Instructions received with the product from previous supplier indicated a baseline 100:1 ratio on the mix.
> 
> 1 ounce = 29.57 ml
> 1 drop = .05 ml
> 
> So... 5 drops/1 ounce would be .25 ml/29.57 ml or .0084545 ml. (_roughly 1/100_)
> Roughly back to the 100:1 baseline ratio.
> 
> While it will vary dependent upon the amount of catalyst used, and Colin has certainly way more experience playing there than I, and notes, just so the suspense doesn't do you in while he's off doing his Burt Reynolds imitation this weekend...
> 
> At the stated 100:1 ratio, pouring 1"x 1"x 2 1/4" pen blanks, approximately 35 ml per blank, total of 185 ml resin and roughly 2 ml of catalyst per batch. I was right around 45 minutes in from adding catalyst, before bubbles started suspending in my cast sitting on the table saw, at conditions slightly warmer than what you mention above.
> 
> That of course will vary dependent upon size of the pour and rate of exothermic reaction.



Thanks for the info, it's a starting point for my education process.....a couple years ago, I bought some of the "inlay" material from "www.woodturnerscatalog.com", along with some of their various metals, and crushed stone. If I remember correctly, the ratio of resin/catalyst was the same as the Silmar product.....I wonder if it's the same? I don't expect my order to be here until late next week, so I've got some time to think about it....


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## rocky1

Rocky1 said:


> or .0084545 ml. (_roughly 1/100_)



That should read 100:0.0084545 ratio not .0084545 ml. My apologies, was trying to get that penciled out for the benefit of all before going to work this morning, and got lost in figuring.

I was actually kind of glad to see the drops used in the equation, because occasionally I run into a small batch that simply doesn't compute in the little measuring cup, and you're stuck guessing. I want to say it starts at 2 ml., so anything less than a 200 ml. pour. Roughly 6 3/4 ounces, you're guessing with the little measuring cup provided.

I'm still getting educated here as well!!

Reactions: Thank You! 1


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## larry C

barry richardson said:


> A trick for bartop, not sure if it would work for this, is to sweep the surface with a torch, the heat expands the bubbles and brings them to the surface... (in the liquid state of course) before it sets up



@barry richardson , I just recieved the 2 gallons of Silmar 41, after seeing that it's extremely flammable, I think I'll pass on the torch idea.....thanks for the thought though!


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## larry C

Schroedc said:


> I'll pull my notes on Sunday abd get you some guidelines to start from. I'm in a play this weekend





Schroedc said:


> I'll pull my notes on Sunday abd get you some guidelines to start from. I'm in a play this weekend



@Schroedc , Colin, did you ever find your notes about the Silmar 41 we talked about last week? My shipment of 2 gallons arrived today, I'm hoping to pour a couple 
things this weekend. I haven't calculated the volume of the pours exactly, but I'm guessing it will be somewhere about 8 to 10 ounces (in volume, not weight) each pour.

If I understand what I've read, and what you guys have told me, this should figure at around 40 to 50 drops of MEKP?


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## Schroedc

Yes, half the chart amount I'd what I'll use to slow it down. If you heat the resin much over 90-95 it'll set really fast even with the catalyst cut back. I like to get it warm to the touch so it flows smooth (fresh resin will generally pour easier) I add the catalyst, stir about 90 seconds, you should be able to tell it's mixed, and then pour right away.


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## larry C

Schroedc said:


> Yes, half the chart amount I'd what I'll use to slow it down. If you heat the resin much over 90-95 it'll set really fast even with the catalyst cut back. I like to get it warm to the touch so it flows smooth (fresh resin will generally pour easier) I add the catalyst, stir about 90 seconds, you should be able to tell it's mixed, and then pour right away.



What sort of heat (exothermic) should I expect?


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## Schroedc

larry C said:


> What sort of heat (exothermic) should I expect?



It'll get warm, if it's getting too hot to touch you've added too much catalyst

Reactions: Agree 1


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## larry C

Schroedc said:


> It'll get warm, if it's getting too hot to touch you've added too much catalyst



I think for the first project, I'll cut it back by a drop per ounce and see what happens. Thanks for your help, I'll let you know what happens.


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## larry C

@Schroedc, I just poured the first pencil holder with Silmar 41. Mixed 12 oz resin, 48 drops of MEKP to catalyze, poured into a mould filled with 
chopped up colored pencils.....so far very few, if any bubbles.....after about 45 minutes, it hasn't kicked yet, but it's a bit cool here today, about 67 or so..


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## Schroedc

larry C said:


> @Schroedc, I just poured the first pencil holder with Silmar 41. Mixed 12 oz resin, 48 drops of MEKP to catalyze, poured into a mould filled with
> chopped up colored pencils.....so far very few, if any bubbles.....after about 45 minutes, it hasn't kicked yet, but it's a bit cool here today, about 67 or so..



Put it in the sun to warm it a bit if you want, or you can also use an oven with a keep warm setting (About 100-120 degrees) to move it along as well although I wouldn't use that oven for food afterwards

Reactions: Agree 1


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## larry C

Schroedc said:


> Put it in the sun to warm it a bit if you want, or you can also use an oven with a keep warm setting (About 100-120 degrees) to move it along as well although I wouldn't use that oven for food afterwards



Actually, at exactly 2 hours, it did finally "kick", I can live with that. I'm impressed so far, no bubbles that I can see, I used a 1 liter milk bottle, cut in half
for a mould.....I think it'll work fine. At least, I've got a bit of a feel for how this stuff reacts....my wife wouldn't let me put it in the oven though. All you guys
mentioned the smell from the resin, it wasn't bad at all, I had the shop door open and good ventilation..

Reactions: +Karma 1


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## Schroedc

larry C said:


> Actually, at exactly 2 hours, it did finally "kick", I can live with that. I'm impressed so far, no bubbles that I can see, I used a 1 liter milk bottle, cut in half
> for a mould.....I think it'll work fine. At least, I've got a bit of a feel for how this stuff reacts....my wife wouldn't let me put it in the oven though. All you guys
> mentioned the smell from the resin, it wasn't bad at all, I had the shop door open and good ventilation..



Good ventilation is a MUST, I prefer to pour and then put outside if weather and temp allows. The isocyanates in the hardeners used in a lot of urethanes and resins are really bad for you, they can build up over time and you get sensitized to them and then one day you hit a point you can't be exposed to them any more. Seen more than one old school body man have to retire because of that.

Reactions: Agree 1


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## rocky1

I've got plenty of ventilation in the shop, and it still stinks! Alumilite is much nicer in that respect. But, I've always found the aroma of fiberglass resin pleasant for some odd reason.

Maybe cause it smells like fishing boats! 


Glad to hear it's working well for you Larry!

Reactions: Thank You! 1


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## chanser123

I cast mine with alumilite under pressure and worked great!

Reactions: EyeCandy! 3 | Way Cool 1


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## larry C

gman2431 said:


> Dont know much about this at all but my first guess would involve a pressure pot.




OK, yesterday, I bought a 2 1/2 gallon pressure pot. Haven't tried it yet, I have to change some of the "plumbing" to make it do what I need it to do.... The "popoff" valve
for some reason leaks, so I've gotta get a different one....This one is certified for 60 psi, from what I've read, most people seem to use 50 psi for casting....
Your thoughts?
Larry


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## larry C

chanser123 said:


> I cast mine with alumilite under pressure and worked great!
> 
> View attachment 125789




Now, those are cool......maybe a little bright for a duck blind though, maybe you could find some camo pencils?


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## gman2431

larry C said:


> OK, yesterday, I bought a 2 1/2 gallon pressure pot. Haven't tried it yet, I have to change some of the "plumbing" to make it do what I need it to do.... The "popoff" valve
> for some reason leaks, so I've gotta get a different one....This one is certified for 60 psi, from what I've read, most people seem to use 50 psi for casting....
> Your thoughts?
> Larry



Sorry Larry I don't do any casting only stabilizing. I'm sure someone who does will chime in on pressure needed.

Reactions: Thank You! 1


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## Don Ratcliff

My advice, when eating sushi the green stuff is used like jelly. For best results use liberally.

Reactions: Funny 2


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## larry C

gman2431 said:


> Sorry Larry I don't do any casting only stabilizing. I'm sure someone who does will chime in on pressure needed.



Regarding stabilizing, is there any reason the same pressure vessel used for casting, can't be used to stabilizing also.....provided one has a suitable vacuum pump? Seems to me 
that it would work, but then I've never tried..


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## gman2431

larry C said:


> Regarding stabilizing, is there any reason the same pressure vessel used for casting, can't be used to stabilizing also.....provided one has a suitable vacuum pump? Seems to me
> that it would work, but then I've never tried..



I use an old pressure pot so yes thats more than possible. I have an acrylic lid for mine for stabilizing but I could always put the metal one back on and use it for pressure.

Reactions: Thank You! 1


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## rocky1

larry C said:


> Regarding stabilizing, is there any reason the same pressure vessel used for casting, can't be used to stabilizing also.....provided one has a suitable vacuum pump? Seems to me that it would work, but then I've never tried..



No reason it can't be, aside from the fact that you can't see if you're pulling air out of whatever you're stabilizing Larry. You simply buy a gauge that goes both ways, screw an airline quick coupler on your vacuum hose, and whichever you want to plug in to the pot you're good to go. If you need a link, Amazon carries the gauges, and I have it somewhere on my account; they're pretty reasonable.

Couple of the guys above, stated in another thread hereabouts that they had picked up a piece of 3/4" Plexiglass and plumbed that for the Vacuum side, which would be a simple solution. I have both, and therefore I frequently find something to toss in both when I'm in the shop. In fact, it's not uncommon to have Vacuum Pot, Pressure Pot, and Toaster Oven all cooking at the same time when I get shop time.

Harbor Freight will warranty the pop off valve, if you carry it back. And, they do carry the valves separately too.

From what I've seen in assorted threads on the topic, most of the guys running the Harbor Freight Pot typically run about 50 PSI with it rated 60.

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