Need help with this vacuum bagging issue.
I am making a carbon fiber car part I have done all steps to seal the part.
For some reason the pump will not pull out the air from the bag.
you can hear it sucking the air out but never pulls the bag down.
I can put the hose on my finger and it pulls full vacuum.
I checked for leaks and cannot find any.
Thanks for your interest.
Hi…you have a leak that you haven’t found that Is with 100% guaranty. Are you using a stretchalon vacuum bag? These are bad for having creases on the sealant tape and most likely allowing air thought this crease. A good method for detecting leaks is getting a 1/4" flexible hose like the kind you get for the ice maker on you fridge. Try sticking one end in your ear and running the other end around your part, mold, tape, bag and suction fitting. This method has always served me quite well. Hope this helps you.
How big is the part? Or more importantly, how big is the bag? Depending on the size of your pump and the volume of air in your bag, it’s possible that it is actually evacuating the air but it’s just taking longer than you expect. I did envelope bagged a part this week using a 3m x 1.2m tube bag, and that took 10-15 minutes to pull down. Blocking the hose will work very quickly as there’s very little air in the hose for the pump to move.
Otherwise, yes you’ve got a leak. And if your pump can’t pull the bag down then it is a BIG leak.
sounds like a leak in the bag to me… it doesn’t take that big of a leak to keep the bag from sucking down properly to the point where you can’t hear the leak. If the part isn’t that hard to bag, or it’s not that big a bag, then just rebag it.
what sort of vacuum ports are you using? Often times it could be the port. If you have any wrinkles under where the port closes, will cause a leak.
is the bag sucking down at all?