This topic is in response to a PM I received asking about felt breather cloth and how can I reuse it. I figured pictures would help.
I also understand the few who vacuum bag here have their efficient ways of doing things. These are my methods I use and work for me with essentially reusing all materials except for peel ply.
First pic is the felt breather cloth that is sold by any store that has vacuum bag supplies.
The vacuum bag itself.
I have 10 different bags set up marked 6’, 7’, 8’…to 15’
The bags are actually 6.5’, 7.5’… etc to give you 6 inches of wiggle room with even sized board lengths.
The all are clamped off on the suction nipple end with a neatly two foot taped breather cloth on that end, inside of the bag.
Here is the pic.
When I vacuum bag a board I use green type release film. This protects your bag and breather cloth from epoxy. If I were to use peel ply, that would be directly next to the board and covered by the green release film.
pic below of green tinted release film
So now I have my board wrapped in release film. I now put my breather cloth on the board.
I have a nose section that is already taped up for quick application. I choose a piece long enough for the board. Flip around the tail and tape off.
This breather cloth in the pic is 3 years old and had done hundreds of pulls and is still kicking.
Also note, this was a mock up and my green release film would be tightly taped off and not hanging loosely
Now you put it in the bag and seal off the open end 3/4 of the way with your bag clamp. Hook up your suction to your nipple side and turn on pump.
I stick my dust collector hose, when off, on the open tail side, finding some breather cloth to suck on with hose. Turn on dust collector hose for 10 seconds the get 90% of air out of bag.
Take dust collection hose out and seal tail of bag completely and then pull your bag smooth were and if needed for you specific pull.
Example of top and bottom being done.
When your vac pull has set and you take every thing out. All the stuff is reusable.
Vac bags last 40-60 pulls, maybe more.
Green release film will last for months
Felt breather cloth will last for years.
Bag clamps will last 5 years.
Now some details. If you get an epoxy spill and it hardens on the breather cloth, just cut the hard piece out and it will prevent dents getting pressed in your wood or glass or forming a hole in your bag with the next vacuum pull.
If you are bagging glass to foam only I use peel ply with no holes, then the same as desctibed above. The breather cloth needs to stay off the fiberglass because it will put an impression of the texture of the felt on your soon to be hard glass. It helps if you have an assistant to help get your wrinkles out of all and any layers toughing the glass. A few wrinkles here and there will not be a problem. using a paper towel for this situation might solve the breather cloth wrinkle worry(I have never done it myself)
Here is a recent pice of a vac bagged texaluminum cloth with peel ply as described above. I think it came out better than expected having no help when doing it.
Over the long haul, if you do lots of boards, the vacuum bagging materials are very little of the cost of doing business. I probably replace the reusables every 7 years. It is always nice to have extra for emergencies. Everything in my opinion is dirt cheap and even more so when you realize how long it lasts or how you can save a step in a board build. All the advice from others on sways on what to use for vacuum bagging materials seems on a scale to very practicle to you have to be joking. I have never persoanlly used any of these techniques so I am only quessing from experience.
Nothing was not mentioned in regards to setting rockers or specific layups for flex. This would not change the basic techniques/supplies needed to vacuum bag at a low cost and reuse most supplies.
Thanks for the primer. Nice and KISS.
I just scored a Gast pump for $20.00 off Craigslist. This info will be handy.
Mahalos.
