I think a post-cure at 50-60C for your polyester moulds would be a good idea. You can remove PVA using warm soapy water. The wax you can remove using a special Mould Cleaner.

After you've done your post-cure and re-applied the wax and pva, although it's not a 100% gaurantee, you could try applying some epoxy and glass to a small section of your mould, letting it cure and then trying the release. If you have release problems on that small section then you're certainly going to have problems on the full mould. At least this way you don't risk either your full mould or all of the materials to make a full part.

I think given a post cure and sufficient coats of wax you should be fine though.

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Thanks for the adivce, i am now concerned about my moulds

The moulds are polyester with a layer of polyester flowcoate (3 weweks old), pva release and about 5 coates of release wax. should i expect problems?

Should i cure at 50/60 deg for 24 hrs if so should i remove the wax and pva?

Thanks

Hi Jackflash,

Joe's advice is spot-on, as are the calculations for your resin quantities. Paul's put together a useful guide for calculating resin consumption here:

Resin Infusion Resin Usage Calculation

When you use Soric as a core, additonal flow media (infusion mesh) is optional. In the new video series (sneak preview of part one available through this forum) we use a full Soric core in the part and still choose to use mesh over about 2/3 of the part but, having watched how it went through the section of the part with no mesh, it would certainly have infused before the resin started to gel even if we'd used no mesh at all.

Your polyester mould is a worry for an epoxy part. If it's an old mould that's done lots of pulls then several coats of wax, like Joe says, could well get you through but if it's a 'green' mould (i.e. new) then leave it as long as you possibly can and ideally give it a post cure at maybe 40 or 50 degrees for a day or so before use to get all of the styrene out of it. A good rule of thumb is to smell the mould. If it smells of styrene (the main 'smell' of polyester) then don't use it yet. Avoid chemical release agent at all costs, an epoxy part will probably not come out of a new polyester mould using chemical release agent. If your mould was epoxy or vinylester (like our Uni-Mould) then this wouldn't be a problem at all, chemical release agent would give you a perfect release.

There is no different epoxy for diolen, Soric, carbon or kevlar. They all simply require a low viscosity epoxy with very high cured mechanical properties. Paul posted some amazing figures on how much better the IN2 (and EL2) mechanicals are compared to a well known epoxy like West 105 in this thread, just in case there's any doubt about just how good our resins are!

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Also i just noticed you are using polyester mold with your epoxy part. Then you need to pay extra attention to surface preparation. The first part i ever made was a carbon/epoxy part made in a polyester mold. Thats not the better idea ever, however, waxing my mold 12 times (maybe a bit overdone héhé) lead to decent release properties. I had to use a little of pressurised air persuasion, but mold had many tight curves. Also, I heared that polyester mold would shrink a bit with time going by.

As most people here would say, always use compatible products to work with. Epoxy mold for epoxy parts, polyester molds for polyester parts. You can also find "multi purpose" products, that will work with epoxy, polyester and vinylester. On EC website, they have this.

Cheers from Belgium.

 



 


    A $1000 electronic device will always protect a 10 cents fuse

Hi, Jack.

For the amount of resin, you can calculate approximately like this:

People usually want a 60/40 reinforcment/resin ratio. So, for your 300 g/sqm diolen, it would be 120 g resin per sqm, PER LAYER of cloth.

For the 3mm thick soric, EC website says it takes 1.3kg per sqm.

You then need to calculate how much sqm you have on your part, and deducting how much resin you will need regarding how many layers of cloth/soric you are using. It's always a good idea to mix a little more resin than theorically, depending which process you choose (hand layup or infusion). Typically, hand layup will take more resin than infusion.

If you are using resin infusion process to make your laminate, you wont need breather cloth. Infusion stack with soric would be mold surface/reinforcment/soric/reinforcment/vacuum bag, as mentioned on EC website.

Breather cloth would be usefull for vacuum bagging a hand wet layup. It would act as a "excess resin catcher" thru  perforated release film.

Also, if you are making a cored composite, you will want it to be balanced, which means you have to put equal layers of same cloth on each side of the core. Example: 2 layers 300g/sqm diolen then soric then 2 layers 300g/sqm diolen. This would ensure the part would not deform during cure.

I hope it helped.

 



 


    A $1000 electronic device will always protect a 10 cents fuse

thanks  

lay as follows

nose Layup: area  500 x 500 mm 

                200gsm 2/2 twill carbon fibre

300g plain weave diolen

                2mm Lantor Soric SF

                300g plain weave diolen

                200gsm 2/2 twill carbon fibre

 

foot tray Layup: area 800x1000 mm

                200gsm 2/2 twill carbon fibre

300g plain weave diolen

300g plain weave diolen

                2mm Lantor Soric SF

                300g plain weave diolen

                300g plain weave diolen

                200gsm 2/2 twill carbon fibre

 

are there different formula's of epoxy  for the carbon,sordic and diolen

would i need to use the supplied soaker matt on this layup ??

thanks in advance

Hi Jackflash, I moved your post to the starter kit area so the team can answer your questions and also so other newbies searching will find answers in the same place.

to help the team if you can say rough surface area and number of layers of diolen and thickness of soric as they will be more accurately be able to guide you on the resin quantities needed.

in terms of tacking down the area you have cut, on one of my projects i have a similar overlap from a cut, i used a small amount of mixed resin to tack it down. Its a fine balance between using enough resin to hold it in place while laying up, and using so much that it could effect the infusion.  I found too much resin and too fast an infusion will mean a few pin holes where the overlap is as the resin will have partly cured by the time you infuse it. But the solution is simple, just go slow.

Hi , whats the epoxy amount for

300g diolen                                        

3mm Soric    

all so i have the breather cloth in my infussion kit,but its not mensioned in the video?  do i use it ?

i have a male corner in my mould and have cut the material to fold around it, is it possible to tack down the skicky out bits within the mould, if so what with? 

i am using wax ontop off a pva (polyester resin mould) as a release will this be ok

 

many thanks