erikgreen
Captain
- Joined
- Jan 8, 2007
- Messages
- 3,105
Hey all -
I've started experimenting with vacuum bagging (and soon resin infusion) at home, and I thought I'd chronicle things here to gather comments and advice.
I'm working on a winter-long refit project for my 21 foot sea ray, and there are a lot of jobs on it that will be done better or easier with a vacuum bag.
Here's what I've got set up so far:
Soo... I got it all powered on and tested the pump (after blowing the first one out, used pump). It sucked down to about 12" then kept running. After some searching I found the bag material I was using, which is 2 mil polyethylene, had torn a couple small holes. I was shrinking it around a section of 2x4 for the heck of it, just to try it all out. I patched those with tuck tape and got up a little higher... but it still leaked. Then I discovered the wood I had the bag on had holes (serves me right for grabbing stuff from the scrap pile to try this with). Once those were taped, I got up to 18"... the pump is supposed to be able to get to 25 microns, so I had lots of leaks.
After searching some more I tightened the clean-out on the bottom of my reservoir and used some JB weld to seal the tubing attachments at the end... then I remembered I could have just tried some tape. Messy solution. But I got it mostly sealed, up to 25", and the pump cut out for the 10 seconds at a time the leak took to raise the pressure again.
I also tried a thicker 4 mil poly sheet, it leaked a bit too and didn't stretch as well. I may get some professional bagging material and try that just to compare today.
I also will probably re-do the reservoir... I need to use more glue to seal the ends on, so they won't leak (I'm using PVC primer and cement). I wish there was a better way to do the clean out hole thing, that big screw plug tends to leak. I could use a different material like steel (I have an old pressure pot for sandblasting) for that, but it'd be harder to clean out. Hmm.
More news as experiments warrant. I'll try to take some pics tonight, too.
Erik
I've started experimenting with vacuum bagging (and soon resin infusion) at home, and I thought I'd chronicle things here to gather comments and advice.
I'm working on a winter-long refit project for my 21 foot sea ray, and there are a lot of jobs on it that will be done better or easier with a vacuum bag.
Here's what I've got set up so far:
- Nylon/polyester taffeta fabric from JoAnn fabrics - peel ply
- mesh flow media from Express Composites
- Polyethylene plastic sheets (painter's drop cloths)
- Harbor freight 3 cfm vacuum pump (I had a robinair surplus pump that died as I was setting this system up... grrr.)
- Vacuum controller from veneersupplies.com
- 1/4" interior diameter vinyl tubing with fiber reinforcement, 20', home depot
- many brass fittings from harbor freight, 1/4" pipe one end and bayonet on the other
- aluminum air manifold, harbor freight
- aluminum vacuum bag fitting, Express Composites
- 4" PVC pipe overflow pot/reservoir, parts from Home Depot
- vacuum gauge from veneer supplies.com
- relay from the local surplus place
- tuck tape, clay, etc. + misc bits from all over
Soo... I got it all powered on and tested the pump (after blowing the first one out, used pump). It sucked down to about 12" then kept running. After some searching I found the bag material I was using, which is 2 mil polyethylene, had torn a couple small holes. I was shrinking it around a section of 2x4 for the heck of it, just to try it all out. I patched those with tuck tape and got up a little higher... but it still leaked. Then I discovered the wood I had the bag on had holes (serves me right for grabbing stuff from the scrap pile to try this with). Once those were taped, I got up to 18"... the pump is supposed to be able to get to 25 microns, so I had lots of leaks.
After searching some more I tightened the clean-out on the bottom of my reservoir and used some JB weld to seal the tubing attachments at the end... then I remembered I could have just tried some tape. Messy solution. But I got it mostly sealed, up to 25", and the pump cut out for the 10 seconds at a time the leak took to raise the pressure again.
I also tried a thicker 4 mil poly sheet, it leaked a bit too and didn't stretch as well. I may get some professional bagging material and try that just to compare today.
I also will probably re-do the reservoir... I need to use more glue to seal the ends on, so they won't leak (I'm using PVC primer and cement). I wish there was a better way to do the clean out hole thing, that big screw plug tends to leak. I could use a different material like steel (I have an old pressure pot for sandblasting) for that, but it'd be harder to clean out. Hmm.
More news as experiments warrant. I'll try to take some pics tonight, too.
Erik
