Question re. Polyurethane resin

[DSD]

I've been using a 1:1 mix liquid resin for casting.

My question is this: If I add less catalyst than the amount specified, will the resin:

a) Take more time to cure?
b) Not cure as hard?
c) Not cure at all?

In short I'm wondering if the catalyst determines hardness, or time to harden. Anyone enlighten me?

 

[Mollins]

where did you find a 1:1 PU Resin?

That seems like a stupidly high amount of catalyst!

I would say though, if the manufacturers instructions specify a certain mix, then use that, never go below, as it will likely not cure at all.

 

[Cheungkinmen]

where did you find a 1:1 PU Resin?

That seems like a stupidly high amount of catalyst!

I would say though, if the manufacturers instructions specify a certain mix, then use that, never go below, as it will likely not cure at all.

I don't know how polyurethane resin works, I guess it's the same as Epoxy resin which you combine equal amounts of A and B to cure, but I think you are confusing it with Polyester Resin which works with a catalyst named MEK. With polyester resin you use 1 cc or less for a X amount of resin to cure.

I hate polyester resin...

 

[Mollins]

I don't know how polyurethane resin works, I guess it's the same as Epoxy resin which you combine equal amounts of A and B to cure, but I think you are confusing it with Polyester Resin which works with a catalyst named MEK. With polyester resin you use 1 cc or less for a X amount of resin to cure.

I hate polyester resin...

I derped, I am thinking of polyester resin lol

I use polyester, and find it easy enough to work with, and it's a lot cheaper and easier to get in the uk

 

[betomatali]

mm depend of the type or quality of your resin in some cases take more time to cure, or maybe not cure hard, of not cure at all , catalyst determines only the time to cure, not the hardess
Why you not try whit the Smoth-on brand? they has a lot of hard and soft 1:1 resins with diferent cure times I use "Smooth-Cast 320/321/322"

I find this info on line:
United Kingdom
Bentley Chemicals Ltd.
Rowland Way
Hoo Farm Indust. Estate
Kidderminster, Worcestershire DY11 7RA
England
Tel: 011-44-1562-515121
Fax: 011-44-1562-515847
Contact: Chris Warren
[email protected]
https://www.bentleychemicals.co.uk/

Bentley Chemicals ltd
Marshall's Yard
Trout Road
West Drayton
London
UB7 7RS
Tel - 01562 515 121
Fax - 01562 515 847

 

[DSD]

Thanks for the helpful replies.

I should clarify, the resin I've got worked fine, it was just that I had a problem with air holes in my mould, and I wondered if a longer set time would allow me to "top up" once I had popped an air bubble that had formed in an easy to reach place.

Silly thing to want to do really, the correct thing would be to fix my mould. But I just wondered.

 

[betomatali]

you can eliminate the air bubbles using a preassure chamber, you can make one whit an air compresor and a big Paint Tank, I make one and my resin cast dont have bubbles
take a look of this!! https://amp.rokket.biz/docs/amp_easy-resin-casting2_pressure_web.pdf