Talk Composites - The Forum for Advanced Composites

DIY Vacuume chamber

http://www.talkcomposites.com/Topic1290.aspx

By ant... - 4/17/2012 2:21:26 AM

Buying a decent size vacuum chamber costs upwards of £1000 but all we really need is some plastic tubing, thick plastic sheet to cap the ends, pvc hose and silicone.

The problem has always been how to get an airtight seal at the opening, well I found some airtight foam strips/sticky backed that were being sold to carpenters to hold down work with a vacuum, but the product was expensive and cut into thin strips Vacuum Workholding Product.  
So I trawled the suppliers database and found out the raw material was made in a town bordering my own.  Munsch & Co make all types of airtight foams and they can sell you a sheet as large as you need at a very cheap price. 

Ive got a 30cm x 30cm square metal baseboard, covered in airtight foam, with a hole drilled in the middle which is connected to a vacuum pump that id bought from carbon mods.  If i place any jar over the middle and turn the vacuum pump on the pressure pulls the jar into the foam creating an airtight seal.  The beauty of this system is you can change the size of belljar to suit your job, a coffee jar is good for degassing and I use a big clear plastic tube for larger jobs.

Pics coming soon...
By ant... - 4/24/2012 10:06:20 PM

im still having problems with infusing/voids.

IMO the process for a great finish is: first remove air, then infuse resin (prepreg = apply heat, infusion, vac chamber = inject resin)

Ive done lots of testing on how to get rid of air bubbles and voids with wet layup by applying cf inside clear jam jars and vacuum bagging, I found their was no process that could remove the air bubbles, not manipulation, vacuum or heat.