Vacuum Bagging Material

[Extemporaneous]

Can anyone tell me if the product below would work for odd shaped, somewhat large (12 ft. X 10 ft.) project?

Let me know if you know.

Thanks,
Extemp.

Reinforced Polyethylene Film
This heavy duty reinforced poly film is exceptional in resistance to punctures or tears yet remains lightweight and flexible for ease of handling.

• 10 mil thick, 8 year rating, resists cold-crack
• 3-ply laminate with a high strength cord grid
• white film allows 20% light transmission (utility use)
• clear film allows 80% light transmission
• UV protected for maximum sun protection

[Evan]

Sounds very nice. I did multiple 8' x 12' foam sandwich panels and just used 6 mil builders plastic. Worked fine and quite inexpensive. 95% of my leaks were at perimeter pleats by the way.

Does odd shaped mean it has sticky up bits? If so, you need to add pleats to allow the bag to properly press on the laminate, otherwise the bag will "bridge" and push down everywhere.

[knottybuoyz]

10 Mil is pretty thick. It's not going to stretch under vacuum and depending on the complexity of the part you might end up with a lot of bridging.

[clockwork orange]

This looks like the stuff we use for temporary buildings over boats we cant fit in the shop, it would work fine for large uncomplicated shapes but if you have any complexity you want something without the reinforcing so it will stretch more.
Steve.

[Extemporaneous]

Ya, I think it might be better without the reinforcement.
I really want to try vacuum infusion and I think it may require a bit more vacuum then simply vacuum bagging which is why I was looking for something thicker/tougher then 6 mil poly, but still reasonably priced.
I would start (vacuum infusion) with some VERY simple/small parts/shapes.
Any suggestions for cheap vacuum infusion/bagging materials.
For instance, I ran into a sailor that built his own cat. He said he used nylon fabric from a local fabric store for a separator sheet and that it worked well.
Anyone?

Regards,
Extemp.

[Oceansandmts]

For a few small parts and tests, inexpensive film, bleeder, peel-ply, etc would be OK, although they may not work as well, but if you graduate to bigger, more complex parts, you will have enough money in fabric, core and resin, and more than enough of your time in getting it all ready, that you will not want to take chances with anything but the best in film, seal tape, vac pump, etc. A failure of almost any part of the system means you have lost your investment of time and money in the part. I don't want to chance it. Just my opinion after infusing some big, complicated parts.

[Extemporaneous]

Originally Posted by Oceansandmts

For a few small parts and tests, inexpensive film, bleeder, peel-ply, etc would be OK, although they may not work as well, but if you graduate to bigger, more complex parts, you will have enough money in fabric, core and resin, and more than enough of your time in getting it all ready, that you will not want to take chances with anything but the best in film, seal tape, vac pump, etc. A failure of almost any part of the system means you have lost your investment of time and money in the part. I don't want to chance it. Just my opinion after infusing some big, complicated parts.

Makes perfect sense, however, I don't want to ignor the possibility of there being parallel products that are just a good but not sold under the label of custom specialty (read more expensive).
That said, if there isn't, then there isn't.

Also my previous post should have said peel-ply not separator sheet.

Thanks and your point is well taken.
Extemp.

[Evan]

I built all the cabin panels of my boat (16 sheets of 4x8 corecell) using fabric store nylon as peel ply. Worked fine. Make sure you search the "remnants" section because they sure had a lot of neon magenta that sold for $1/m there

[knottybuoyz]

With some research and some trial and error you will be able to find alternative materials from cheaper sources that work just as well. It'll take some research & experimentation though.

I've used the fabric store nylon materials as peel ply and some landscaping plastic mesh as flow media. I've also used shade cloth as flow media which produced the best results so far (other than purpose designed flow media). The one thing I haven't really found a good alternative for is the bagging material. I've tried poly films that are available in the hardware stores, plastic shower curtains, garbage bags (not bad for small parts) etc. None of which I'd feel comfortable using on a large part involving $1000's of other expensive materials.

Other consumables such as bag sealing tapes (butyl rubber) can be had cheaply from RV supply stores, they use it to seal windows. I've gotten it as cheaply as $2.50/roll for a case of 24. I use all hardware store water supply plastic pipe and T's from Lowes for the resin feed and vacuum lines. I built my own resin traps from hardware ABS pipe & fittings. My pump (Robinair 15500) came off of e-Bay for $200.

The process by itself produces a lot of waste material. That's probably one of it's biggest drawbacks for the hobbyist. Unless you can buy in large volumes (economy of scale) you'll pay a premium for these materials. If I was building a whole boat say worth $50K then $200 for a roll of Stretchelon isn't so bad. If you're near a boat building company that uses this stuff you might ask if they can get you a deal or sell you some roll ends etc.

There have been some innovations in the materials used such as core matting that's also a flow media that stays incorporated in your layup. I think it's called Enkafusion.



The white tube on the right is the resin trap. it has a clean out plug on the bottom. The black tube is a vacuum reservoir I plumbed into the system ' cause I had it. You can see the Robinair on the left.

I don't like to leave electrical equipment running unattended so I added a vacuum control setup to run the pump when needed.



Details on how that works can be found on the joewoodworker.com website. I think I put the whole thing together for less than $350.