Page 4 of 5

Posted: Tue Mar 26, 2013 4:45 pm
by JSquare
I'm out of my element here-- Silicone doesn't stick to much. This may be of some use to you:

http://www.compositescentral.com/archiv ... -4494.html

"I saw the video of them doing a hood bag.they used silicone tape around the edges.then some reinforcing fabric.then when you use the bag.you use tacky tape to stick the silicone tape on the bag to the tool."

"The trick when you want to use sealant tape, is to apply a double sided tape on the mould flange, and, sticky side up, flash tape (this is kind of fidly). Now when you brush on liquid silicone, it will adhere to the flashtape. The flash tape gives the silicone bag a place for the sealant tape to get hold off. Sealant tape will not adhere to silicone bags! (due to the vacuum you might or might not get a good seal)."

Vacuum Press

Posted: Sat Sep 14, 2013 4:23 am
by Leon87
Hi there

I use the vacuum press system. I think it works just aswell as pneumatic pressing.

People always talk about not getting as much pressure which is true but to be honest thats irrelevant.

The good thing about Vac press is that it doesnt squeeze all the resin out of the ski/snowboard, It draws the air out of it which is exactly what you want.

I work for a well know car compostiies company and thats the exact way the car body parts are made, aswell as wind turbine blades and aircraft parts.

The amount of pressure doesnt play to much of a factor, aslong as its enough to push your materials into the shape of the mould.

I think that a pnumatic press is quicker though as a Vac takes a bit of setting up and then time to lay the release film,breather fabric and vac bag. Plus all these rings cant be reused....

Im running a vac pump i bought off ebay for £30!

Hope that helps


Check out my Facebook Page
Esc.Snowboard Co.

Posted: Sat Sep 14, 2013 11:42 am
by Richuk
How relevant pressure is, depends on the core material and resin technology being used. Pressure is very relevant if you are not using prepreg. If you are using prepreg, it is dependent on the resin technology employed by the supplier.

Posted: Sat Sep 14, 2013 12:22 pm
by Leon87
I Know what you are saying. But most resins will react to temperature regardless of what pressure it is pressed at.

We use alot of different resins at work. all pressed with vacuum and heat.
Some of our stuff is prepreg which we use as it cuts down on mess and waste.

We used to make the resins for alot of the ski industry. SP 106 and 206. I think its now called west.
I used SP206 last year and was really good.

The core material will have an effect yeah. But for the thicknesses skis use then its not a problem.

I really recomend Vacuum pressing. When done well it can achieve amazing results. Check out RAMP, Deep Skis, theres a french builder swell whos skis look incredible but i cant remember then name....

Posted: Sun Sep 15, 2013 4:19 am
by Richuk
Boheme skis.

There's nothing wrong with vaccum, but its important to point out that it is sub-optimal for a hand layup. The issue of resin ratio's can be fixed by setting up a small resin impregator. The issue of void content remains.

Posted: Fri Nov 21, 2014 12:17 pm
by backyardskier
ok this might not be the best place to be asking this. That aside: some thoughts on this pump? http://www.veneersupplies.com/products/ ... 0-VAC.html

I know 3 cfm is a bit low, but for that price it is hard to pass up.

Posted: Fri Nov 21, 2014 12:40 pm
by Idris
backyardskier wrote:ok this might not be the best place to be asking this. That aside: some thoughts on this pump? http://www.veneersupplies.com/products/ ... 0-VAC.html

I know 3 cfm is a bit low, but for that price it is hard to pass up.
Wouldn't be worried about the speed - much faster than my old fridge motor - made 10 pairs of skis with that!

Posted: Fri Nov 21, 2014 1:18 pm
by pmg
Too bad they don't show the Model number of this pump. A very common pump from Thomas is the 26xx models, mostly the 2660. Have a 2650 now and am completely satisfied!

Re: Vacuum Press

Posted: Thu Sep 19, 2019 11:46 pm
by colin123
I’ve been looking round at vacuum presses, and admittedly it’s getting a little hard to select one. When shopping for a bandsaw, jointer, or anything, there are masses of resources that evaluate models and brands available, now not to say the remarkable remarks from Knots. However, I’m having trouble figuring out what vacuum presses are top or now not. I’ve checked all the huge WW catalogs, some hyperlinks from this internet site, in addition to veneering books.

I realise that: thicker plastic is better, stronger vacuum pumps are better, bigger is better, but that is one of these things- I have a 14″ bandsaw due to the fact I couldn’t justify the 20″ version. I can’t just blow my coins on the largest and first-class without batting an eye.

Re: Vacuum Press

Posted: Wed Oct 09, 2019 10:51 am
by jcar
Great thread! I’m still in the planning stages and go back a forth about vacuum pressing. Been looking at the Joe Woodworker V4 Plus Project (Venturi). https://www.veneersupplies.com/products ... s-Kit.html
However I live at 5700’ elivation which means I’m gonna loose 2.5psi est. right off the top. Would this be too much loss in psi for a good press? Has anybody used a Venturi pump for a vacuum press?

Re: Vacuum Press

Posted: Sat Oct 12, 2019 3:38 am
by mammuth
I did build my first boards with the vac-pro venturi + a 25l tank from an old compressor for vacuum "storage", works great. You just need a compressor big enough

Re: Vacuum Press

Posted: Sat Oct 12, 2019 3:28 pm
by jcar
My compressor is a 60 gallon 5hp Ingersoll Rand that is 18 cfm at 90psi. I would think that would be enough?

My real concern is pressing with 2.5 psi less than sea level. My only options for my first few boards is vacuum or a double sandwich press with a ton of pipe clamps? Not sure which one would be better?

Re: Vacuum Press

Posted: Mon Oct 21, 2019 7:20 am
by leahicmoradnuf
jcar wrote: Sat Oct 12, 2019 3:28 pm My compressor is a 60 gallon 5hp Ingersoll Rand that is 18 cfm at 90psi. I would think that would be enough?

My real concern is pressing with 2.5 psi less than sea level. My only options for my first few boards is vacuum or a double sandwich press with a ton of pipe clamps? Not sure which one would be better?
The first board I made was with a jenky vacuum press in my college machine shop (near sea level). The gauge read ~25 in-Hg, a perfect vacuum would've been 29. So I didn't have a perfect vacuum seal, and 25 in-Hg converts to about 12.2 psi.... The board came out just fine. I think you'll be ok with 2.5 psi less than sea level. Also, I think a vacuum vs. sandwich press will apply a more even pressure distribution, unless your sandwich press has an air bladder.

If you're still concerned, why not vacuum press it, then clamp it down as well to get a little extra pressure?

Re: Vacuum Press

Posted: Tue Dec 03, 2019 10:20 pm
by Wvmtnbiker

Re: Vacuum Press

Posted: Wed Dec 04, 2019 2:42 am
by Wheatlpa
That mould is exactly what I am looking to build! Low profile and it looks to be adjustable. Any chance you can send along the build details or point me to where you got the details from?