Moving for polyester to epoxy tooling. Thickness

General Composites Discussions Composites Talk
#1

I have been doung alot of grp work latly, mainly a group buy on a doors for a certain car. I havent done no carbon work for nearly a year now. :confused:

Any way im looking to step away from polyester tooling. Yes its good for my grp work but i will be going back to vacuumm produced items once the grp work has slowed down.

Lets take a bonnet for example. I am moulding a bonnet now, no flanges, as its going to be mainly wet layup and the odd vaccum bag with an envelope bag method. Im currently building it between 8-10mm thick and using paper rope as my ribs/stiffner

If i was to produces the same item in epoxywhat desired thickness would i be looking at? Im comparing both materials and cost of each?

Regards

#2

Same thickness.

Also keep a couple of things in mind:

Epoxy gelcoat is not suitable for polyester production, especially when the numbers get high. The epoxy will not survive the styrene attack.

What problems do you have with the GRP moulds? I can think of heat resistance and smell during production as valid things, but for the rest polyester tooling is OK, especially with the shrink free products like Nord Composites RM2000 and RM 3000 (with the latter being my favourite. Tg of 110C, so usually plenty heat resistance.

#3

Go with a VE gelcoat, VE skin coat and a rapid tooling system.
I use Nord Composites GC206, DSM Atlac 580 and Optimold - respectively.
Available from Polyfibre, East Coast, and Gazechim - respectively.

You should be looking at 4-5 times the thickness of the part being made.

A rapid tooling system will limit you to a certain thickness per layup, or multiples thereof. Optimold for example is around 6mm, so 12mm if you laminate twice. DSM’s Neomould is slightly less at 4-5mm.

#4

Yes i have looked into optimould tooling. Problem is my workshop is not heated. Ambeint temps would be a big problem unless invest in some kind of heating

#5

The large advantage of RM3000 in that respect is that it does NOT need the minimum layup thickness to cure properly and free of shrinkage. Nord Composites really has a great product with that.

On heating: If you cannot get the workshop at 20 degrees C, I doubt you will like to work with epoxy.

#6

Its an issue i will be addressing in the near future heating. Will probably get a large space heater once i insulate the walls.

I will try and find a stickist if the rm300 and read the data sheets. Thanks for pointing me in right direction herman

#7

NORD COMPOSITES UK - Anne Sophie Renotte
Unit 1 / G-Moor Lane Industrial Estate • Perrylwell Road, Witton • B6 7AT Birmingham • France
tel : + (44) 121 35 69 144 • fax : + (44) 121 345 11 02
email : nord-compositesuk@btconnect.com

#8

Thanks for that, Herman. I didn’t think you could get the Nord RTS system easily in the UK. If I looked on their website (which is dog poo btw) I would have seen it! Duh. I’ll give it a shot when I run out of Optimold.

How does RM3000 not over-exotherm? Or more to the point, what makes it zero shrink compared to the exotherm expansion properties of neomould/Optimold/RM2000?

#9

It has the same sort of chemicals (low profile additives), but also a much lower shrink resin (vinylester as opposed to iso resin). Did you find the datasheet already?

#10

Just spoke to Anne from Nord UK, she said get it from Polyfibre (the guys I get GC206 from) for 25kg quanities.

#11

Hello Herman,

do you know where in Germany or Holland I can order the RM3000 and how much it costs per kg?

Regards Reinhard

#12

Netherlands: Brands structural products, part of MCtechnics from belgium. Or get in touch with Herman, Like I do :wink:

#13

You can mail me: hb at brandscomposiet dot nl

#14

Thanks Herman. I will send you a mail