Thread: Pressure pot for resin casting pen blanks

It would be but these from supercheap are cheaper
http://www.supercheapauto.com.au/onl...ecommendations

Bob, I have moved your thread to Penturning-Casting and Stabilisation. If you do a search in that forum you will find a lot of information put up by people that have gone before you.

You could even start with this one

https://www.woodworkforums.com/f204/pressure-pot-76319

If you want to nick over to dandy I can help you convert to pressure pot.

Its not that difficult, A few parts and taps from BGS.

From what I can see no modifications are needed. All I would suggest it that you line the bottom with some plastic so that when you spill some resin (and you will spill some resin eventually) it won't stick to the bottom of the pot.

Originally Posted by brendan stemp

From what I can see no modifications are needed. All I would suggest it that you line the bottom with some plastic so that when you spill some resin (and you will spill some resin eventually) it won't stick to the bottom of the pot.

I drive my paint pots horizontal.
That way I don't need to remove the vertical pipe the paint would use taking space.
I just align it at the top.
Then I slide in a ply shelf for the items to sit on/ spill on.
get 3 shelves that way.

Thanks, Brenden, Fly and Big Shed. I spent an hour last night reading some previous posts and have one issue I would like clarified.
In several posts temperature was mentioned, in particular one suggestion that one should not cast when the temperature was below 30 degrees. Hey, we southerners might not get another day over 30 in the next 6 months or more. So how do you guys down here cope with our weather conditions?. I did note one post suggesting wrapping the pot in an electric blanket - is that a realistic option? I only have an unlined steel garage to work in.

Thanks for your assistance.

Bob

PS Thanks for the offer Fly. I have to go to Dandenong next Monday - I will send PM

Do not cast if below 30????? You can heat your resin by suspending your resin in hot water (eg your cup in a bucket).

I wasn't sure about this 30 degree mark either.

Yeah if you warm the resin in warm water it will flow a bit better, but I do nothing about the ambient temperature.
If you get it to warm it will gel quicker which is ok if you want to do the 3 or 4 colour swirly blanks but no good for embedding.
Dai Sensai is the expert so we'll go with what he says.

Peter

Edit: It was Neil that said it,
https://www.woodworkforums.com/f204/casting-pressure-183593
Now he has to explain himself....

I bought a 10Ltr pressure pot from Super Cheap and finally set it up this afternoon following advice from Peter (_fly_). Took a while to get caps to close off the hose outlets- no-one locally had them in stock


Connected to the compressor and was suprised to find that I could only get 38PSI before the pressure relief valve 'blew'. Only have 50PSI at the outlet of the compressor. Operating instructions with the pressure pot state a maximum pressure of 50 PSI. Salesman at Super Cheap says that the releif valve should 'blow' at 40 PSI.

two questions:
1. Have I got a faulty unit which should be returned?

2. Is 38PSI sufficient for casting resin - mainly pen blanks?

Thanks for your advice

Bob

Bob,

Mine goes to 50 psi?
I do remember that I need to get the pin facing up or it will blow earlier.
Try it with nothing inside the pot and have the ring and pin of the relief valve facing down and then do it facing up.
See if you get a difference.

I just read the instruction sheet from supercheap and it says if the pressure relief goes of "reduce pressure to between 20 and 50 PSI"
So its meant to handle 50 PSI.
Its on the bottom of page 6,

Page 5 says not to use OVER 80 PSI.

Maybe check it standing as intended as well.

Ask them to swap the pressure relief valve.

Guy you spoke to was obviously talking rubbish.

Originally Posted by _fly_

Bob,

Mine goes to 50 psi?
I do remember that I need to get the pin facing up or it will blow earlier.
Try it with nothing inside the pot and have the ring and pin of the relief valve facing down and then do it facing up.
See if you get a difference.

I just read the instruction sheet from supercheap and it says if the pressure relief goes of "reduce pressure to between 20 and 50 PSI"
So its meant to handle 50 PSI.
Its on the bottom of page 6,

Page 5 says not to use OVER 80 PSI.

Maybe check it standing as intended as well.

Ask them to swap the pressure relief valve.

Guy you spoke to was obviously talking rubbish.

Yes we read all that, but he still insisted that 40PSI was the point at which it should release. The pressure relief valve is in the factory installed position coming out of the "T" piece in the horizontal plane. The regulator and pressure gauge are connected to the other side of the "T" piece via an elbow and stand vertically.

They have agreed to replace the unit if I am not happy, but there's not much point indoing that if it is operating correctly or only needs a simple adjustment / change to the installation layout. Have I set it up correctly?
_DSC3150.jpg








Apologies for crappy photo, but didn't have a flash handy.

Thanks
Bob

The orientation of the valve should not make any difference to the pressure at which it relieves. The spring inside is what sets the pressure, not gravity.
The fact they are probably made in China, there is likely to be a fair amount of variation from one to another at what pressure they go off at.

Like all these "mass produced things" you will get variations within tolerances, these are meant to spray paint in the end, we just use them differently . That said mine blows at about 45 lbs , I set my pot to max at about 40-42 lbs so it doesn't keep blowing and losing pressure , Never had a problem at that pressure for casting ,remember that compressed air is quite cold and slows down the setting of your poly quite considerably. you can add a bit more of the activater to speed things up a bit ,but usually need to leave overnight under pressure for sure results . I try and heat my pot in the sun before use , we get some useful sun here in Queensaland hehe. Even when left overnight it can still feel a bit sticky out of the pot ,thats when "post curing " in a small toaster oven is handy . Back to the pressure relief valve I seem to remember a few years back I got a small washer and dismantled the unit ,and placed the washer behind the spring to beef it up a bit , and get a bit more pressure , but if the unit is rated at max 80 psi ,it could be that plugging the relief valve off, and setting the tank regulater to 50 PSI could be another option ( WITH CARE ) All the poly products shrink on setting as well and just make sure you have a bit more in your mold than you need to allow for shrinkage . Its all good and the range of special blanks like pinecones worthless wood and a good number of other things you can think of is never ending . So enjoy cheers ~ John

I got given wax in styrene (small jar).
I use a few drops in the polyester resin and it takes the sticky away that you always get on the exposed surface.
The faces inside the mould don't seem to get sticky.

Another way to post cure is just put the heat gun on them for 20 seconds and then let cool. Cures all the sticky.