My first vacuum resin infusion attempt...

Discussion in 'Boat Design' started by Wynand N, Nov 21, 2008.

  1. Wynand N
    Joined: Oct 2004
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    Location: South Africa

    Wynand N Retired Steelboatbuilder

    I decided to do my first attempt at vacuum resin infusion today. Made myself some bleed and resin connectors on the lathe and got busy.:)

    Since it was just to get the feel of it, I decided to go for a worst case scenario and use the little low volume Gast vacuum pump that only pulls a 57kpa vacuum compared to the bigger ones that pull about 88kpa with a healthy flow.

    I set up a glass board, pva it and put down 3 layers of 450g csm with a 600g wr tucked between it. I divided the cloth length wise in three parts, first with an improvised peel ply with decent holes in the material, second one with similar material with fine holes (got this material from the local coolie cloth store for next to nothing) and the third no peel ply at all.
    On top of that I placed the resin flow mesh, and in this case I improvised again and used 40% shade cloth. The bleed and supply fittings and lines were fitted and a piece of old plastic place over all that.

    I must make it clear that I need to see how different of materials will work before I attempt experimenting on real laminate schedules with the decent vacuum pumps hooked up.
    As it may, the little Gast pulled a vacuum to about 57kpa and when I blank the vacuum pipe off, the envelope puffed up immediately and I new I had a leak, but due to carelessness some csm strands were sticking out over the tacky tape and this was perhaps the leak, but what the hell, I let the resin flow...

    On this trail laminate I used polyester resin with 1.4% normal hardener to see how far it will go until **** happens as it was a typical hot and humid SA day. As it turned out, the mix lasted 17 minutes and then started to gel and I lost about 150ml in my feed pot.

    When the envelope was taken off, the shade cloth popped off by itself as if it was allergic to resin, and the peel ply's came off easily. The average thickness of the laminate is 1.7mm and although the trail was not done with every thing weighted and measure, my rough calculation shows about 30/70 resin to glass ratio.

    Some observation worth sharing;
    I just put the shade cloth down without giving the weave any consideration, and as it turned out, the main weave was in the direction of the flow/infusion, and whilst under vacuum, one could clearly see how the resin flowed through these "channels". If the main weave was fitted across the flow, I personally think the attempt should not went as smooth as it turned out to be, more so with the shitty pump I used.
    Secondly, I think an additional 3 inch wide strip of shade cloth (folded 3-4 times)placed on top of the main layer of shade cloth under the resin feed tube, will help greatly to get the resin running - perhaps wrapping the feed lines a few times with the cloth instead of placing a strip under. Will experiment with this idea.:cool:
    Lastly, no obvious difference in the rate of infusion between the peel ply's and the strip without. Must be good stuff :D

    Monday will see me pack an actual laminate with coremat applied, use the same resin mix, but with my new 6cfm JB pump, or that big 1hp pump (Edwards?) I have on standby, and no leaks.....wish me luck

    The photos below: 3 of the fusion in progress and the fourth one of the improvised peel ply's - line 3 had no peel ply other than the shade cloth.

    Attached Files:

    2 people like this.
  2. Wynand N
    Joined: Oct 2004
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    Location: South Africa

    Wynand N Retired Steelboatbuilder

    and most importantly, thanks Andrew for your advice, information, links and the time you spent answering my emails. Whenever in Oz again, I'll by you a few of those beers Oz is famous for...:cool:
  3. KnottyBuoyz
    Joined: Jul 2006
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    Location: Iroquois, Ontario

    KnottyBuoyz Provocateur & Raconteur

    Nice work Wynand. It's fun learning infusion that way. I've done some of those experiments myself. I learned a few things.
    1. When you spill epoxy on the laundry room floor just don't drag the carpet over it.
    2. It's a bugger trying to get uncured epoxy out of your hair
    3. It's near impossible to comb cured epoxy out of your hair
    4. Advise the Admiral where you spilled the epoxy so she doesn't walk through it!
    5. Check the back of your hands for uncured epoxy before you wipe your forehead with them!
    Seriously though. I found a larger field beyond the parts and the "gorilla snot" (mastic tape) helps a big deal with isolating leaks. (see pic)


    I picked up a "spy ear" on e-Bay that works wonders in finding leaks. It's a toy but actually works. Think they cost about $3. Or if you want you can pay a couple hundred bucks for the real thing.

    I set up my pump to automatically turn itself off when it reaches a preset vacuum level. Just a little leary about leaving electrical equipment running un attended.


    All the parts and instructions on setting up your pump are on the web site. Other benefits are, the pump doesn't have to run continiously, less noise etc. Makes finding leaks a breeze.

    The first parts I did were a test the setup. I actually made a cover for our sump pump hole.



    All of this of course is leading up to building a boat. I'd rather tinker & learn it's just my way. Lot of learning to do though before risking tens of thousands of dollars on a full hull infusion.

    Here's a few sites I've found informative.

    Keep the projects coming.
  4. Fanie
    Joined: Oct 2007
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    Location: Colonial "Sick Africa"

    Fanie Fanie

    Nice start Wynand, from here on it's going to be easier and easier and better and better.

    I'm going to attempt a new rudder for the tri as well as a swivil sheeth for it over the weekend. Will see how it goes.
  5. Fanie
    Joined: Oct 2007
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    Location: Colonial "Sick Africa"

    Fanie Fanie

    This way you can do a boat a day eh, you realize that ?
  6. TeddyDiver
    Joined: Dec 2007
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    Location: Finland/Norway

    TeddyDiver Gollywobbler

    Most informative and...

    where should I ask for a vacuum pump?
  7. StrandedMariner
    Joined: Sep 2007
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    Location: Shanghai, China

    StrandedMariner Steelboatsailor

    Wynand, it seems you are on the right track there. Good luck!

  8. Steam Flyer
    Joined: Aug 2008
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    Location: North Carolina, USA

    Steam Flyer Junior Member

    Great post & pics, thanks

    I'm a little unsure what you mean by "shade cloth" but other than that, a very helpful post as I grope towards my own vacuum-bagging system. As of now I have built two hatches, one vacuum-bagged and one not; and a mast-raising gantry on which the vacuum failed with the resin 75% cured. Infusion may be quicker & easier than vacuum bagging a wet lay-up but it looks like you have to have a bit higher level of technology and be better organized. ;)

    It's a lot more work than building with steel, I betcha!

    FB- Doug
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