opinions on my method?

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#1

Hi all although i joined awhile ago i havnt really posted on here ive just been reading and reading my workshop is finally set up and all my materials/regins/gel coats etc are ready.

stupid as it sounds ive actually started off by trying a difficult part to make (complete interior kit for my car) im certain that 90% of the molds will be fine but the main console has many different angles and lips and im worried about distorting the weave oh btw im using 200g twill carbon and 390g fibreglass epoxy resin… im happy with my molds appart from one and heres where the advice is needed… when i demolded the original a small part of the gelcoat came away from the mold fortunately it wasnt in an area thats required in fact it is in an area thats going to be cut away from the finished product…

my question is can i simple bond this part back in place? or should i do a fresh mold? and also im beginning by wet layup curing at room temp until my vac pump arrives,

#2

and im planning on using the vac infusion system but at first want to play with wet lay my only concern is that due to the angles etc that once i lay the fabric into the grooves etc im going to be left with uneven/ or badl laid fabric so basically any opinions on how to lay twill on complex parts would be excellent also any products you have made that you found to be complex would be interesting to see?.. Thanks ste

#3

If the damaged part of the mould is going to be cut away on the final part, then by all means, epoxy it back on there. Or if its just the gelcoat you can just sand it out.

As for playing with wet lay, I would steer well clear of that on a complex part. Especially if you are planning to do it through vacuum infusion anyway. You will end up with a part that is full of voids, ugly weave, and a high percentage of resin if you decide to wet lay parts with lots of angles and complex shapes. You will have trouble keeping the fabric down.

spray tack (best use an epoxy interface) is your friend, as is of course, vacuum consolidation.

cheers

#4

hi bajapatient spray tack? meaning epoxy resin sprayed to allow material to bond? or is there an actual spray tack ? thanks for advice after having a good look at my molds i dont think ill struggle that much tbh perhaps im being over precautious my main concern was the damage to the mold but after having a good think about it i could make the repairs and then set the carbon dependant on quality after demolding i could then make a fresh mold from the new part and as its a solid piece i wont have to worry about any problems with mechanical lock etc etc … ill post up results soon!

#5

There are several methods to fix dry layers of reinforcement to the mold when doing a vacuum infusion layup.

My first part was quite complex and laying it in there without any adhesive was a disaster, tonnes of voids.

Some people apply a gelcoat and let it get to tacky stage, then apply the first layer of reinforcement to get it to stick.

I have done one with industrial spray glue, it worked quite well, but the glue remains in the laminate which is rather unwanted.

I then came across a spray adhesive which is epoxy based, its called stayz by zyvax, its quite pricey, but it does the job, the glue fuses with the dominant resin system and becomes part of the laminate.

would be good to see your results!

cheers