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[nhp651]

Quick answers please................is polyurethane resin supposed to split crack and shatter.............I always thought one of the properties of this quick setting resin over the normal grp polyester resin was that it was NOT supposed to do that even when fully cured.
I have always found that when working it, it was plyable and even carvable when fully cured.
got a batch the other day and used it yesterday and today, and it even shatters when splitting the silicon rubber moulds in half...........even polyester resin doesn't do that.
think I've got a duff batch and it's a company I used for the first time.
neil.

[CF-FZG]

Neil, I'm a bit confused here, as polyester is a member of the polyurethane family

Mark.

[Subculture]

AFAIK, PU resin is distinct from polyester resin.

Cured PU resin should be very tough, almost indestructible if post cured in an oven- not necessary for most stuff. Never heard of it splitting when demoulding, what's the brand- so I can avoid it!?

I use Smooth-on 300 range PU resin, excellent stuff, but not cheap.

[wartsilaone]

Hi Neil,

I use easyflow 60 polyurethane for my models and I like it because I can drop small delicate pieces without them breaking.

This stuff should have flexibility but I do find that some times it doesn't cure properly, maybe because I didn't shake the bottles before use or got the mix slightly wrong or even it's a bit cold.

I've noticed that the liquids sometimes look different between deliveries and if I order larger amounts it seems to be different too.

I would do so more testing.

Ali 

[Umi_Ryuzuki]

Depends on it's formulation.
There is house brand made by TAP PLASTICS, that is so brittle, I won't even recommend it.
Fiberlay also has a house brand that is 100/90 mix, and it fairly durable, but still a bit brittle for small or thin parts.
Polytek Easy flow 60 has always been a solid performer. I am not sure how that compares with SMOOTH-ON products.

:)

[nhp651]

I mix it in a graduated set of little "jugs" so the mix is always 1:1 or as near as can get it....temperature in my workshop is always about 60 -70 F and I have done no diferent to what I used to do......but the resin is so brittle it's unreal..have made about 6 different sets of moulds over last 2 days and all come out ther same..totally unusable.
was told on RCMB by a mate last night ( oh I do have some, lol) that there are two grades that modellers use a PU365 which is brittle and a PU364 which is the stuff that I normally use.......well the one advertised on their web (and I didn't know there were diferences) is the PU365 the brittle one..........but they don't mention this on the web..just that it's excellent for casting for modellers.....well it's not.......it's useless for fine detailing......so a phone call today.
I won't mention the company as I have already made it clear that it's not fair to do this on open forum, but if anyone wishes to know the product.......if I don't get satisfaction today.pm me for the product name, .....but I'll be going back to my old supplier who supplied all for the Clyde class lifeboats 70- 001 and 70-002

neil

[hopeitfloats]

I mix it in a graduated set of little "jugs" so the mix is always 1:1 or as near as can get it....temperature in my workshop is always about 60 -70 F and I have done no diferent to what I used to do......but the resin is so brittle it's unreal..have made about 6 different sets of moulds over last 2 days and all come out ther same..totally unusable.
was told on RCMB by a mate last night ( oh I do have some, lol) that there are two grades that modellers use a PU365 which is brittle and a PU364 which is the stuff that I normally use.......well the one advertised on their web (and I didn't know there were diferences) is the PU365 the brittle one..........but they don't mention this on the web..just that it's excellent for casting for modellers.....well it's not.......it's useless for fine detailing......so a phone call today.
I won't mention the company as I have already made it clear that it's not fair to do this on open forum, but if anyone wishes to know the product.......if I don't get satisfaction today.pm me for the product name, .....but I'll be going back to my old supplier who supplied all for the Clyde class lifeboats 70- 001 and 70-002.



if its the same website i have been looking at there wasnt much difference in the spec's of pu 364/365.  no help to you but may be a mistake loading the info to their site. it will be interesting to hear their explanation if you plan to post it here.

[nhp651]

Well Guys, many thanks for all your help and advice.
the problem is now sorted.
I rang East Coast glass fibre supplies this morning and spoke to the technical advisor called Martin......and he couldn't have been more helpfull and apologetic for my dilhema and totally understood what I was trying to do..........in their defence the technical data sheet says that the minimum thickness for a mould is 3mm, and I was trying to mould 4mm thickness so was right on the edge.
Martin agreed with me that the resin was not suitable for what I was wanting to do, and as such said that if I reurned the twin pack of resin to him he would give me a full refund for the product, even though I had opened the tins and used a little.

I CANNOT ASK FOR BETTER SERVICE THAN THAT, and my thanks and praise go out to East coast fibreglass supplies....many thanks.

neil.