Vacuum Pressing

[Raymond]

I am looking for information about vacuum pressing and its associated equipment. I am interested in hearing from those that bought systems complete or built one at home; brands and sources. What are the lessons learned? What works and what doesn’t?

[crfabbro2F]

Company called Fiberglast has an online store wth everything you would need. YouTube is
a good source for seeing how to vacuum bag.

[Raymond]

Thanks Chris,

I see lots of good process ideas on you-tube but not much about the supporting hardware. Have not seen the site mentioned: will check it out. Thanks

[Yellowjacket]

Fiberglast is a good source for a lot of the accessories, like bags and fittings and hoses, but they charge a lot for the vac pump. I found a suitable used pump on ebay for around 100 bucks that works great for what I was doing. Make sure you have a pump of sufficient capacity and make sure it is rated for continuous duty vacuum work and you will be fine. I bought my pump from ebay vendor bluelooneym and they have a lot of experience with these pumps. I got a 5.5 cfm pump because I wanted to do larger areas, obviously you need a bigger pump to do bigger stuff, but if you undersize the pump it will be a big hassle, so oversize if in doubt.

[mark5pa]

Let me add a question. I am going to do mostly flat panels, knee board & cockpit side. Is it worth vacuum bagging, or should I just use weight between 2 flat surfaces? If I do sandwich with weight, can I still use the perforated release film with the mat to soak up excess epoxy? Or just wax the flat surfaces?

[Yellowjacket]

Even with a lot of weight you can't get nearly the same pressure as if you use a vacuum system. You'd literally have to put tons of weight on it to make it work the same.

In my experience, the vacuum comes out a lot flatter and nicer than trying to use weights. Been there and done that. If you are doing a 1 foot square surface you can get a pretty decent flat surface using weights, and a sheet of mylar (.030 thick or thicker) but as you go bigger, it becomes more wavy and the extra effort to finish it makes it harder to get a nice surface.

For the mylar trick, you lay up the glass and wet it out and then put the mylar on the surface, and then roll out the bubbles and the excess resin, and then put a weight on it. It won't be as smooth as a proper vacuum pressed surface, but it will look pretty nice.

I would think that you would get bubbles if you just tried to flat press the top surface on and that would be a disaster. It would take literally tons of pressure to try to get the bubbles all out. The mylar works because you can roll the bubbles to the edges of the piece and since it is clear, you can see the bubbles and work them out. I would think that you couldn't do that with flat sheet that you couldn't see thru and it would be a mess.

[Ron Hill]

I Can't of the Company's Name

I am looking for information about vacuum pressing and its associated equipment. I am interested in hearing from those that bought systems complete or built one at home; brands and sources. What are the lessons learned? What works and what doesn’t?

The name will come to me, but maybe you can Goggle it. They sell everything to build airplanes with. They are in Corona, California. They sell various vacumm bagging pumps.

Name might be Spar Lumber. Yes! SPRUCE SPAR STOCK from Aircraft Spruce


http://www.aircraftspruce.com/catalo...esparstock.php


SPRUCE SPAR STOCK Aircraft spruce spars are available either S2S ... Thousands of feet of S2S aircraft quality spruce are stocked in our Corona, CA. warehouse. ... Orders are often delayed awaiting delivery of lumber to the even footage ...

[G Stillwill]

When I make combing sides I just sandwich the carbon fiber or kevlar between two sheets of plywood. I have a big flat table that I lay them on with lots of weight. The A and B boats I use two pieces of 3 mil for the combings for the bigger boats you might want to use something thicker.

[Ron Hill]

Epoxy Glue?

George makes a great point...George, do you use West Systems epoxy?

Or what do you use?

[mark5pa]

When I make combing sides I just sandwich the carbon fiber or kevlar between two sheets of plywood. I have a big flat table that I lay them on with lots of weight. The A and B boats I use two pieces of 3 mil for the combings for the bigger boats you might want to use something thicker.

This was my plan exactly George. I have a big piece of flat slate for a flat surface, and plenty of lumber to get even pressure. Also have some truck load bars to go off the ceiling, to get some extra pressure.

[Raymond]

Company called Fiberglast has an online store wth everything you would need. YouTube is
a good source for seeing how to vacuum bag.

Chris,

That is a great resource: Thank You

[Dave M]

In Battle Creek

I have a complete set up. Give me a call sometime and i can talk shop with you. There are local sources for supplies.

[mark5pa]

The only vinyl foam core (corecell & divinycell) suppliers I have found only handle 4' X 8' sheets, that have to ship common carrier. I would imagine the freight would be as much as the board.
Any ideas??

[Raymond]

I have a complete set up. Give me a call sometime and i can talk shop with you. There are local sources for supplies.

Thanks Dave,

Can you send me your number via HR message or otherwise? I do have a few questions you could guide me on. Such as; is there a standard final as laid up thickness dimension per layer of a given weight of carbon fiber fabric? Example; how thick would each layer of 19.2 oz/sq yard 12K, 10x10 create?

We are converting a 25SSH transom to accommodate a Yamato. In replacing the transom not only do we need to come up, we also want to bring the last foot of the side comings up to support the top of the higher transom. The current thought is to splice-in to get the desired height and sandwich the comings from the inside and out to support the splice. The splice will be the same thickness as the coming. The outer sandwich layers will consist of one layer of 3mm okoume plywood with an as of yet undetermined number of carbon fiber layers laminated to it for ‘thin strength’; one on the inside and one on the outside each coming. The cockpit is skinny and we don’t want to lose too much width. We also don’t want to add to much out in the airstream. The inner and outer sandwich layers will come forward about a foot and slant down towards the front for a clean transition line. The transom will be a full replacement.

What do you think of the claim in the ad shown below? Will this a vac-u-clamp vacuum pump work for laminating? Is there a difference? The add is from Johnson’s Workbench up in Charlotte. Harbor Freight has a couple of vacuum pumps but…I am leary of those. I don’t really want to spend full dollar for a system I think I can build for much less by piecing it together.

Raymond
raymondpb@aol.com

[BillCNC]

For bagging, ... I get my stuff from here. http://www.cstsales.com/vacuum_bag.h...FQLZQgodgUgA6Q

If you scroll the site, ... they will have everything you'll need and the prices are good.

For a vacuum pump, ... Gast is the only ones I use. Similar to these, ... oil-less and continual run. Any of these will work.

http://www.ebay.com/sch/?_nkw=gast&c...d=442741603297

http://www.ebay.com/itm/Gast-DOA-P10...item1c2f894cdc

Pumps like the ones I listed (not mine, nor do I know the people) are made for continual running so you don't need reservoir tanks, switches and such. Just the pump, line and bag fitting if you chose to use one. Also, do yourself a favor, get the mini quick disconnects for the vacuum line, ... you wont regret it!

Remember, when it come to vacuum bagging set-ups, ... use the K.I.S.S. formula. To many people get frustrated with complicated systems.

Regards
Bill