PR casting help please

[Steve68]

Hi all.

I'm about to have my first try at casting some PR blanks. I read on here (I think it was Brad) said that with PR you don't have to use a pressure pot / vacuum chamber. So as this sounds an easier option to start with I'm going to try PR first. Apparently warmth helps with air release so would I need to warm the mould or is it an idea to put the poured blank and mould into a warm oven?#

Any help will be much appreciated.

Steve.

 

[Sawes]

Warm the resin and warm the mould too.

With PR if you slightly warm the main part of resin it will become more liquid. Don't get it too hot as when you add the mekp it can set too quick.
A slight warmth in the mould can help with curing. Also a little vibration can help bubbles rise if there is some still trapped when you pour.
Careful mixing will also help reduce how many bubbles are introduced

Sent from my SM-G925F using Tapatalk

 

[Woody]

I used to stand mine on the table of my fretsaw and start it up plenty of vibration after warming soon shifts ant bubbles you may have just watch the mould don't vibrate off the table lol

 

[Penpal]

Ultrasonic vibrator is used to do this task. You are coming into your cold time weather wise if you make a simple box or tub to warm the mixture it can be a great help.

Peter.

 

[Bammer]

Don't do it in the house, the smell is quite strong and your wife will not thank you for it.

But it will take longer to fully cure in a cold shed.

Moisture is not your friend, even the dampness in the air will add moisture to your mold.

Probably not the best time of year to start experimenting.

 

[Steve68]

I insulated my summer house and put a heater in there so its nice and toasty even in the colder weather. I can leave the heater on for an hour before experimenting.

 

[wm460]

I insulated my summer house and put a heater in there so its nice and toasty even in the colder weather. I can leave the heater on for an hour before experimenting.

Come on Steve, stop swearing no four letter words allowed.

 

[wm460]

Read some where you switch on your B/Saw and put your blanks on the table.

 

[Dibbs]

I haven't used any vibrating device and have had bubble free results so far. Don't put it anywhere too warm either. I once put the mould on top of the central heating boiler and the resin discoloured (scorched?) at the bottom of the silicone mould. That was a bit scary. It made me wonder about a possible fire risk.