Vacuum Bagging: update

[Bob Perkins]

Hi Everyone,

I made my first attempt at vacuum bagging this weekend and wanted to share the results:

Here is the second layer of the transom being clamped onto the first. On the floor is the pump setup that I got instructions on how to build from Joe Woodworker (http://www.joewoodworker.com).

Essentially - it is a vacuump pump with holding tanks (Schedule 40 PVC) to buffer the system so the pump doesn't run continuously. Also, there is a vacuum switch, gauge and power switch. The actual pump is not visible in the pic.

http://www.imagestation.com/picture/sraid98/p7e984b037d839e4f586fc911ea057ff6/f9fe739b.jpg

I had a few glitches to start, but learned a few things. First, System 3 with slow harder is too slow when the shop is 56 degrees. The transom took a day and a half to get dry enough to make me want to remove the bag.

I used medium on the second glue up and that went much better. A section of the bottom yesterday using medium only needed 10 hours of vacuum. I may try the fast harder since I will only be doing 15 Sq feet of area at a time.

Second, The yellow mastic stuff is REALLY sticky - but not necessary for the big flat areas. I used duct tape the second time and it worked just as well but without the cost. I'll only use the yellow stuff to seal leaks in awkward shaped spots for now on.

I have a couple more things to try to improve efficiency - but I'm really happy with how it is coming out so far.

Thanks to those who provided guidance on this

-------------
Regards,
Bob Perkins

My out of date site is at:
http://robert.perkins.home.comcast.net/

My Current project is at:
http://www.imagestation.com/album/?id=4291051329
-------------

[Bruce Hooke]

Looks good! That PVC pipe setup is a clever arrangement.

[warthog5]

Bob What pump did you end up using?
What CFM?

[imported_Conrad]

It's fun, huh! I always felt as though I'd never use a staple again after building canoes from bagged meranti (1/16"). It is so incredibly effective for gluing large areas. :D

[Bob Perkins]

I ended up using a 4.5 CFM Gast pump. After speaking with the manufacturer I found out it is rated for continuous duty (although it gets really hot, they said that's normal - it has a thermal protector to prevent meltdown. I put a small fan on it just to feel better).

It has kept up just fine doing about 12-14 Sq feet of area. I'm going to try adding a few more sq. feet this PM.

The breather fabric really gets stuck in pretty good when it wicks up the squeeze-out - not sure if there is a better way to do that. The Fein Multimaster with scraper blade does a good job of cutting it away.

Vacuum is SO much better that pulling a thousand staples...

I hope it works as well at the more shapely areas smile.gif

Take Care,
Bob

[warthog5]

[QUOTE]Originally posted by Bob Perkins:

The breather fabric really gets stuck in pretty good when it wicks up the squeeze-out - not sure if there is a better way to do that.

Are you using peelply on the wood first, before you lay the bleeder cloth?

[Bob Perkins]

Nope - (I love learning curves....)

Does the *excess* epoxy pass through the peelply? - or does it just spread it around?

I seem to remember reading that peelply is just some sort of fabric you can get at a fabric store to save $$$ as opposed to buying something with the word *marine* on it.

Any help here is appreciated too.

Thanks,
Bob

[JimConlin]

That's the miracle. Epoxy squeezes through the peel ply and when it's kicked, you can peel the peel ply and breather layer off at once, leaving a flat, slightly textured epoxy surface which needs little sanding before finishing. The weave of peelply is fairly tight, so the 'necks' of epoxy passing through the pores of the cloth are small and easily broken.

[ 01-13-2004, 01:53 PM: Message edited by: JimConlin ]

[imported_Conrad]

Yup, that's the trick. You either have to use all the tech, or non at all`. I finally decided to just use plastic sheeting with some polyethlene rope under it, laid on in a loose pattern to help with the air evacuation. In all honesty it worked just as well as the fancy set-up 99% of the time, and saved a lot of money! ;)

[JimConlin]

And peel ply is inexpensive- about $.13/ft^2.

Moreover, if your epoxy is given to blushing, the blush forms outside the peel ply and gets peeled off. No cleanup needed.

[JimJ]

Has anyone used bubble wrap under the plastic to enable evuacuation?

[John Meachen]

Congratulations on your achievement.It really is quite a challenge to get a satisfactory seal on a wooden structure.You mention the breather cloth sticking to the resin that has squeezed out.Have you considered using release film first?It is not the same material as peel ply but is just a very thin plastic film.For composite moulding it is made in either perforated or non-perforated form.Sometimes, the perforated film allows enough resin through that the fibres from the breather left on the surface of the job look a bit like a bad hair transplant.For small jobs, I have used supermarket carrier bags for this purpose,definitely cheaper than peel ply.Please post more photographs as you progress with the project.
John Meachen

[Bob Perkins]

Last nights update:

I did another 20Sq feet of area last night - I didn't have official peelply, however through a little research I learned that it is essentially 100% polester (or nylon) fabric.

So I took a shot and got 4 yards of liner fabric from the local fabric shop - slippery stuff.

It worked perfectly - It kinda zips right off the glue lines.

I haven't tried bubblewrap - but the *breather fabric* looks to be the same thing as 100% poly quilt batting also from the fabric store. I don't expect to run out of breather - but if I do - quilt batting is next.

Finally - the fabric store also sells the heavy vinyl stuff that I'm using for the bag, but a lot cheaper... SWMBO is a quilter and she gets all the good 50% off coupons..

My last thing to try is a little more surface area and the more concave areas of the hull as I work my way forward.
-------------
Regards,
Bob Perkins

My out of date site is at:
http://robert.perkins.home.comcast.net/

My Current project is at:
http://www.imagestation.com/album/?id=4291051329
-------------

[JimConlin]

Bob-
You can use 4 mil polyethylene film as a bag. Just provide enough pleats that it won't need to stretch much. Cost is approx $.02/ft^2 at Home Depot.

[warthog5]

You could do this with just using visqueen.
In one way it defeats the purpose of vacuum bagging and this would mainly apply to VBing fiberglass layups.
Using the peelply and bleader cloth sucks out the overage of resign. That's one of the pluses of it. Lighter/stronger laminets.
I have weighed some of my laminets. The best I can get is a 40% glass and 60% resign in a hand layup.

In VBing I can get 60% glass and 40% resign.

[RDWar]

Hi,
Could someone point me to a site covering all aspects of vacuum bagging? Thank you
Ron

[warthog5]

RDWar There is not one site covers all, but here's some.
http://www.bertram31.com/proj/tips/vaccuum.htm

http://www.joewoodworker.com/veneering/vacuumpumpsystem.htm

http://www.expresscomposites.com/vbag.html

Here's abunch of links that deal with composites and some vac bagging

http://www.jetracing.com/composites/composites.html

[RDWar]

Thankyou

[warthog5]

Here's another one that will give you some insite.
http://www.spsystems.com/solutions/solutions_pdfs/pdfs_productdatasheets/vacuum_consumables/vacuum_consumables.pdf

[JimConlin]

See the WEST System booklet "Vacuum Bagging Techniques", available from Jamestown and other low joints.

[warthog5]

Since there is not alot out there on vacuum bagging.
I decided to give lessons. :D

You can see my pix's and text here;
http://www.classicmako.com/forum/topic.asp?TOPIC_ID=157

[TomFF]

Bob - just wondering what your using for veener?

[vikar]

yeh Hi, has enyone tried this with cabon/grp masts? I've seen a few experiments with infalatable manderals, Any veiws on this?.

[Bob Perkins]

Hey TomFF,

I'm using 3MM Okume for the *inner* layers. The final layer will be 1/8" Mahogany veneers.

The building schedule is a total of 3 side layers and 4 botom layers

So far so good - I have quite a few *baggings* (10) left to get to the point where I can start doing the mahogany layer.

Bob

[TomFF]

Bob-
Great progress on the cold molding! I visited your imagestation site. I like how you've documented everything. I noticed one of your first shots was a big pile of 4/4 and 5/4 mahoghany.

Did you cut the veener from stock? If so how did you go about it to get a consistent 1/8" thickness?

[ihrig]

I got my vacuum pump for $14 from an industrial surplus center, vacuum bags as well. I have used bubble wrap with peel ply on cedar veneer. I found this combination left hexagonal epoxy patterns near where epoxy was squezed from between 4" wide veneer strips. The peel ply wasn't held down between the bubbles. Heat gun and hot scraper edge takes off excess epoxy.

Dang I miss finding my shoes glued to the floor!

[ 01-26-2004, 10:10 PM: Message edited by: ihrig ]

[Bob Perkins]

TomFF,

I haven't cut/purchased the veneer yet.

My options are: Buy a bunch of pre-sliced 1/8" veneers or slice my own.

My bandsaw has the capacity and horses to slice up this much wood - I'd then run the pieces through the drum sander to finish them to 1/8".

However - If I can find 1/8" x 4-6" x 6-10' veneers at a price that makes the hours of slicing go away - I may go that route. I have to do this shopping soon.

I know of one place, sveneers.com that does what I need - but no others.

So if anyone has recommendations or good/bad experiences with other vendors - please let my know.

Thanks,
Bob

[On Vacation]

Bob, check this thread, and e-mail Cecil for veneers information.

http://media5.hypernet.com/cgi-bin/UBB/ultimatebb.cgi?ubb=get_topic&f=1&t=007013&p=

[JimConlin]

Bob,
I recently bought some LOVELY 1/16" Honduras mahogany veneer from Edensaw (http://www.edensaw.com)
Don't know whether thicker stock is available.

You might also try
Maine Coast lumber (http://www.mainecoastlumber.com/) . They resaw.

[ 01-27-2004, 12:42 AM: Message edited by: JimConlin ]

[Cecil Borel]

Hey Mike, thanks for the plug! Bob, I would highly recommend "Global Veneers" web page (http://www.globalveneer.com/) . They have the length, thickness, and width you are looking for.
I stapled my veneer, but have followed your vacumn bagging with interest. My album is located web page (http://www.imagestation.com/album/?id=4290272927)

[On Vacation]

Cecil, we need an update, Hint, Hint!!! You guys are missing an operation of the finest kind. If only some of us could have such an ideal building setup. He is quietly creating a masterpiece, by himself, while holding down a fulltime stressed filled job. Before you know it, he will be sailing off into the sunset, in the south pacific somewhere, typing to us by wireless remote, while we freeze to death here on planet reality. :D

[Tomcat]

I've used bubble wrap and it works great, but it's probably best when the thing being bagged is like plywood. It leave octapus marks in cloth (duh), and may not get even enough pressure on veneers, since the bag can acutualy stretch over the bubbles. Worked great on my KHSD tri.

[JimConlin]

Another material that can be used for the breather layer is nylon insect screen. Depending on how much goo squeezes out, you may get several uses from a piece.

[warthog5]

Cecil That's a hell'va shop. Looks more like an office. HeHe I liked the slideshow feature on your pix's.

What did you do to fill the ends in down the keel in this pix? It's hard to tell looking at the other pix's.

http://www.imagestation.com/picture/sraid60/pdd0746bc02a0fc43a06665ef6ccbbfbb/fc3ebf30.jpg

[ 01-29-2004, 04:05 PM: Message edited by: warthog5 ]

[imported_Steven Bauer]

Wow Cecil! What a project. But she sure looks smaller in the launch photo than in the building photos! :D

Steven

[Lion]

Cecil.....wow, what a shop, teriffic naturel light. The project; what design...your own?

Lion

[SAWDUST]

i've found everything i need for vacuumbagging at www.jamestowndistributors.com (http://www.jamestowndistributors.com)

they are now selling a great pump as well as all the supplies. i've been vacuuming surfboards for a few years. i can't believe more people don't vacuum things. it keeps everything light, strong, and cuts down on the finishwork!!!!

[warrenH]

Originally posted by JimJ:
Has anyone used bubble wrap under the plastic to enable evuacuation?JImJ,
well spotted. bubble wrap is used in the fiberglass boat manufacturing business to vac down balsa and foam core material behind the outer laminate before the inner laminate is applied. very large panels are done this way.
you may want a peel ply under the bubble wrap depending on how much grinding off of the resin that comes up.

[ 01-31-2004, 08:47 PM: Message edited by: warrenH ]

[ihrig]

Get your free bubblewrap here! Try clicking on the sheet and asking for a fresh new sheet.

http://fun.from.hell.pl/2003-11-24/bubblewrap.swf

[ 02-02-2004, 05:56 PM: Message edited by: ihrig ]

[Bob Perkins]

Hi Everyone,

My second layer of boat has been vacuumed onto the first. Overall, I did 14 seperate vacuum operations to get the entire layer installed.

For future reference, here are a few things I learned:

You need a peelply layer between the wood being clamped and the breather fabric. I did not use *real* peel ply - but 100% poly liner fabric purchased at JoAnne Fabric. Wife gets 50% off coupons in the mail - So I paid $1.50 a yard.

Breather fabric - had purchased 10 yards from Jamestown ($50). Stuff works great, but it's quilt batting. I got 20 yards of 6oz quilt battting with coupon for $30 today.. Works just as good.

I originally started with the 25ft roll of yellow mastic material to stick down the bag - big waste of money (you can see the yellow stuff in the transom pic) Use normal everyday duct tape to stick the bag down where ever possible and only use the yellow stuff to fix leaks and stick the bag down where tape doesn't work.

Bag Material - I first used this clear vinyl stuff I found at the home center ($1.89/Linear foot) It works great and is somewhat reusable. Then I found the same stuff at the fabric store for ($1.50/yard w/coupon) Better deal. But I was piecing together scraps to make larger areas. Then on a recommendation - I tryed 6mil HomeDepot plastic sheeting. (Price ~$9 / 50 yards equiv of vinyl sheeting). Best yet - disposable.

The vinyl sheeting is easier to work with because the duct tape and yellow stuff stick better - but the 6mil stuff is a lot cheaper and works.

I did not have leaks through the laminates, but the tougher ones to find were edge leaks that had to be sealed from inside.

Overall - vacuum bagging is more expensive and time consuming (especially with a smallish pump, 4.5 CFM) - but I wouldn't trade it for anything else with this type of construction.

I'm using much less epoxy that if I was just stapling - and I don't have to remove thousands of staples when I'm done.

I just started the third bottom layer - largest surface area I've attempted - ~36 sqf. It gets easier and easier with practice.
http://www.imagestation.com/picture/sraid103/pa8ea6279e9e5e3519640dfadbcdc72e1/f9afc7c0.jpg

Next: Bottom gets a third 1/8" layer, then entire boat gets the mahogany finish layer. Below the waterline will get more okume since it will be painted anyway.

-------------
Regards,
Bob Perkins

My out of date site is at:
http://robert.perkins.home.comcast.net/

My Current project is at:
http://www.imagestation.com/album/?id=4291051329
-------------

[chrisk]

Thanks for this thread! I've played around with vacuum bagging using a refrigerator pump. I went ahead and got the Joe woodworking setup you pointed out. It should work much better.

I am a bit disappointed that you consider 4.5 CFM smallish. I went with a surplus 3.3 CFM that Joe Woodworker has. Oh well, too late now I'll see what it can do. Is 36 sq ft the max because of a pump limitation or due to the shape of the boat?

Again Thanks for all the good pointers!

Chris Kottaridis (chrisk@quietwind.net)

[ 02-08-2004, 03:08 AM: Message edited by: chrisk ]

[Bob Perkins]

Chris,

The Joewoodworking setup wooks good for doing veneers in a fully sealed bag. I learned for boat building it is not quite as functional as I originally hoped for. (Hope I didn't steer you wrong here..)

The pump I have is rated for continuous duty - so I normally just let it run for 10-12 hours while the epoxy cures. If the pump you have can't do this - you will likely have problems. I didn't know this when I started btw, that was OJT. For the amount of reading I did on the subject - I really missed a few basic things it seems..

The 36 sqft surface area thing is a function of how much epoxy you can mix up, spread, get planks in place, then covered up and sealed. The glueup is the last thing I do. I have all the planks pre-cut and numbered, all of the bag layers are precut, taped along one edge and folded back. I'm still pushing the edge on this - I just don't want to get into a situation where I can't hear any more leaks and the pump can't keep up with the inaudible ones.

In the end - the pump has to pump faster than the leaks leak. My usual rule is to seal all of the audible leaks and get the vacuum just over 20" HG on the vacuum gauge. I've found that over the next hour, the vacuum usually creeps up to about 21" HG. Not sure why - but it's been pretty consistant.

I also started with small areas and worked my way up in surface area as things became more predictable.

Good Luck,
Bob

[JimConlin]

Bob-
A few suggestions for increasing the area you can do before things get sticky.

Slow the epoxy down by using the slowest hardener available.

Mix the epoxy in small batches. It gets started much more quickly when it's in the cup than when it's spread out. Keep the current batch in a flat pan so that heat of the reaction is dissipated.

Let the workspace and, more importantly, the boat be cool. After the bag is on, you can apply heat lamps to warm the applied resin so it'll penetrate and cure.

Tape up your veneers into one or more sheets after you've fitted them. I use a paper veneer tape from Woodcraft. Amazing stuff. It has a water-soluble glue and sands off easily. As it dries, it shrinks and pulls the joint together.

For sealing the bag, There's another option in between duct tape and super-sticky-vacuum-tape. It's weatherstrup tape, available from Home Depot and the like. It applies a bit more quickly and is a bit cheaper than super-sticky-vacuum-tape.

[warthog5]

Bob your boat is really comming out slick.
I have found that there are about 4 or 5 diffrent grades of Duct tape. I always buy the most expensive stuff and found I use less, as it seals much better.

the other week my Dad was over and I was showing him some Deveacell panels that I was vac bagging. He then told me "You know I have another one of those pumps".
My eye's lite up. The first pump is 1/3hp and the 2nd is a 1/4hp by the same manufacture.
I still haven't been able to get any imfo from the manufacture on these pumps. They have no CFM ratings on them. My guess is the 1/3hp is about 3 to 3.5 CFM.
I already have 2 vac ports for connecting to the bag. smile.gif

[Bob Perkins]

Thanks Warthog5 smile.gif

I'm using a pretty sticky version of duct tape - it has help up well. The poly sheeting is really slippery.

However - the really good news is a tip from Jim Conlin. I stopped at the Depot and picked up a roll of "Mortite". It's labeled as Weather stripping and caulk. It comes in a ribbon of brown clay-like stuff.

Jim - if this is what you are talking about - it works great! It is much easier to use than the vacuum bag sticky tape for sealing leaks.

The vacuum bag stuff is like sticky rubber - this is sticky clay. Much easier to fix holes! And a lot less $$

minor update - I did a ~45 sqft section today. Pump held up great and the weather stip stuff made sealing a lot easier.

Thanks all,
Bob

[ 02-08-2004, 07:46 PM: Message edited by: Bob Perkins ]

[JimConlin]

That's the stuff.

Anybody want to buy a case of 'real man' vacuum tape?

[chrisk]

Trust me, you are steering me a whole lot "righter" then I was steering myself. This is much better then the old refrigerator pump I was using.

Again Thanks!

Chris Kottaridis (chrisk@quietwind.net)

[warthog5]

It's not wood, but this was my latest vac bag project.
It's Divenacell.

http://www.imagestation.com/picture/sraid100/p63dc4d5e9bad8694adb28f3b42d2a1da/f9e73108.jpg

http://www.imagestation.com/picture/sraid100/p4065c834abfb71c86c750ffb9fea8f88/f9e73105.jpg

http://www.imagestation.com/picture/sraid100/p89124dfbbc2ac0b5922730355b109a5c/f9e73103.jpg

http://www.imagestation.com/picture/sraid101/pc91c5f28af8c5b202f8703060191445b/f9df05ea.jpg

http://www.imagestation.com/picture/sraid101/pbd48e36cc19afc8f62fb358c2f466ccc/f9df05e7.jpg

http://www.imagestation.com/picture/sraid102/p1b120a5d36f7ecea341a4e246d0704cd/f9b26867.jpg

http://www.imagestation.com/picture/sraid103/p18d8fec93c21e904bf91742733eb69c7/f9ae23df.jpg

http://www.imagestation.com/picture/sraid103/pa987818587977cbb1543f5ffe0fbdd82/f9aad5e3.jpg

[warthog5]

Next pix's.

http://www.imagestation.com/picture/sraid103/pc97f52048e368ece919d0c2e4eb0aee6/f9aad5df.jpg

http://www.imagestation.com/picture/sraid103/pdbf572b9aa6aca6baa6a58fd62a9307f/f9aad5dd.jpg

The purple blob is excess System 3 Quik Fair.
It;s ashame that stuff cost's so much. It's a really great product.

[ihrig]

Home Depot has the new 3M Clear Duct tape. It is easy to see when you have complete adhesion with clear duct tape.

It is also good for repairing rips on car seats.

[ihrig]

Has anyone here tried vacuum infusion of resin in cold molded boat building?

http://images.google.com/images?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=vacuum+infusion&btnG=Google+Search

I tried a little test panel with 1/16 veneer but wasn't that successful and got some voids.

[warthog5]

That's the biggest problem with infusion. Knowing where to let the resign in so there are no voids.

[Bob Perkins]

Hey Warthog,

Looks good!

For future reference, what layers do you use when doing an all glass/resin layup like you show in your pics?

Mine is:

Vacuum bag material
6oz quilt batting (breather)
Peelply
Outer layer of wood
Epoxy
Base surface wood

Do you use something else between the peelply and resin impregnated fabric? I'd think the peelply layer would just get glued in...

Just wondering.. in case I ever need to make something without wood in it (let's hope that NEVER happens)

Bob

[JimConlin]

Nope. The peelply just peels off, as the name implies. Actually, when you peel it off, you're fracturing the teeny necks of epoxy that go through the weave of the cloth and connect the mass of epoxy on one side to the peelply to the mass on the other side. What's left is a near-smooth surface. Incidentally, if your epoxy is subject to blush, that's on the outside of the peelply. The peelply-textured epoxy is clean and ready for secondary bonding.