I've been looking to make a few bits for my mates sevens, but with work and not having the correct materials to hand its taken until now.
After the issues I had with my first mould (my mistake due to part undercuts) I borrowed my friends machined ali mould, it needed a good bit of prepping as it still had a lot machining marks due to the depth of cuts, but after a 400grit wet and dry start all the way up to metal polish, this was the end result.
I tried getting the tool into my laboratory oven and it will fit but is very tight, and i would still need to run the vac lines and make sure the bag isn't damaged, so I took the chance on trying a bit of wet lay but using a vac bag to give better consolidation and get a bit of the resin out of the laminate.
I have a background in laminating, but with prepregs in the aerospace and Motorsport business. I had forgotten how much I hate wet lay, its messy, the fabric doesn't stay in place and its just generally a nuisance, especially with a short pot life of 40mins with the resin
The resin was starting to go off as i was laying the last ply, I used a 240gsm 2x2 Twill for plies 1 and 3 and 310gsm NCF ±45° to bulk it up, the NCF doesn't drape into such deep pockets very well so i had to dart it and cut into stripes, but here's a photo of it all in the vac bag.
And what was the result you ask? Well I didn't use as much release film as I should have as I was trying to save it, so some of the breather caught to the resin but no big issue.
There were a couple of dry spots and a few pinholes, but the parts are for a race car so I will just give them a quick flood coat of 2k lacquer.
I was thinking of laying the dry fabric plies on some released glass or release film and impregnating them with resin before laminating them into the tool? Would this be a better way of doing it? as trying to wet out the plies in the tool was a real pain even though I used loads of resin and stippled them with a brush.
After a bit of trimming and sanding the parts looked good, I cant recommenced the perma grit tools enough!! the little disc cutter on a dremel was awesome and the sanding blocks make short work of sanding back to the trim lines, wish I had a set of them a few years ago!
For a first quick shot using wet lay and a vac bag, using non-perf release and heavy breather the results aren't bad, the surface finish is of course good as its a polished ali tool. But I need to address the dry spots in the first ply.
Any recommendations on what you would do, and yes I know infusion is the next way or cut the tool in half so I can use prepregs
