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Vacuum bag technique
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Author:  Ruby50 [ Tue May 07, 2019 7:08 pm ]
Post subject:  Vacuum bag technique

I have never used a vacuum bag before but had a veneering project. I am a hand tool user and found a hand operated vacuum pump. It was cheap - under $30 for the pump and fitting - and worked perfectly for the 4 panels I veneered at 11" X 30". They even have pictures on their website of a set of braces being glued on a top.

1) 30 seconds of pumping and here is what I had. I had to pump 2-3 strokes every 10 minutes with a couple of panels, but a couple were OK after the first pumping. This will depend on the seal you get at any openings

2) a close-up. The texturing is the surface of the veneer which is flamed ash

Made by Roarocket, no affiliation, yada, yada, yada

https://www.roarockit.com/woodworking-tutorials-categories

https://www.roarockit.com/tap-parts.html

Ed

Author:  banjopicks [ Wed May 08, 2019 6:26 am ]
Post subject:  Re: Vacuum bag technique

I like this technique and have wondered if a simple space bags would work. I just might try it.

Author:  Clay S. [ Wed May 08, 2019 7:00 am ]
Post subject:  Re: Vacuum bag technique

Hi Ed,
Did you buy the "super pump" or the regular pump? How difficult was it to evacuate the bag?
I made some side laminating forms by thermoforming corian. Presently I use kerfkore and a multitude of clamps to compress the veneer and hold it against the form. Since the laminating form is only 1/2 inch thick it may be possible to fit it in a skateboard bag and vacuform the sides.

Author:  jshelton [ Wed May 08, 2019 8:33 am ]
Post subject:  Re: Vacuum bag technique

Clay S. wrote:
Hi Ed,
Did you buy the "super pump" or the regular pump? How difficult was it to evacuate the bag?
I made some side laminating forms by thermoforming corian. Presently I use kerfkore and a multitude of clamps to compress the veneer and hold it against the form. Since the laminating form is only 1/2 inch thick it may be possible to fit it in a skateboard bag and vacuform the sides.


Clay, I have a vacuum press set-up which I use for laminating double tops and backs but for laminating the sides I prefer clamps. I know other people use vacuum for sides but I just don't trust the vacuum to apply the force needed to press the multiple lams on the sides together. I use an inside mold.

Author:  rlrhett [ Wed May 08, 2019 5:04 pm ]
Post subject:  Re: Vacuum bag technique

Funny how we all develop our own ideas. I’m the opposite. I don’t trust clamps to give me even pressure to laminate multiple layers in a side. So I vacuum it flat for 2 hrs. Once I feel confident the epoxy is set but not cured I take the sides from the bag and press it into a mold. It cures to the proper shape in a mold.


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Author:  Ruby50 [ Wed May 08, 2019 8:51 pm ]
Post subject:  Re: Vacuum bag technique

Clay

It took about 20 seconds of pumping to empty the bag. With the curved/coopered doors there was planty of air space in there, but your sides will have more volume to evacuate.

I sprung the extra $2 for the super pump. I won't be using it anytime soon - you are welcome to take it and the bag to try out when we see each other next.


Ed

Author:  Clay S. [ Thu May 09, 2019 8:26 am ]
Post subject:  Re: Vacuum bag technique

Hi Ed,
Thank you for the kind offer. I will probably take you up on it. It is always nice to "try before you buy". I understand John's reservations about using vacuum, and he may well be right. The corian molds I have made are only 1/2 inch thick so they may fit in the bag better than the block molds I also use.

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