Infusion - Without The Hype

Discussion in 'Boatbuilding' started by CatBuilder, Dec 18, 2011.

  1. CatBuilder

    CatBuilder Previous Member

    Reading online, I'd swear sometimes people confuse "vacuum infusion" with "cold fusion." It sounds like a crazy, high tech super method for creating never before quality.

    Well, this thread is to discussion vacuum infusion as it is experienced in real life. Building boats. No hype.

    What I've found is that it's good sometimes, but not always a good thing.

    The Good:

    *Parts with a bag on both sides
    *Flat parts on an air tight glassing table
    *Parts where you have a very large lamination schedule
    *Doing a build single handed when you can't hand laminate a section that's too large

    The Bad:

    *Trying to infuse onto a core material from one side
    *Trying to infuse to join an "already infused and glassed" area on the same part

    What I'm finding is that infusing simple, flat parts works great. Infusing whole hulls? Not so much, unless you can get a bag around the entire hull, inside and out.

    I infused rudders and dagger boards. I infused half a hull. I will still infuse my cross beams, deck house and roof top. These all make sense to infuse because I can get a bag around both sides of them.

    The hulls, however, make little sense to infuse unless you are using a true mold, rather than a form. I am now about 60 hours into trying to find all the leaks on my latest hull infusion and it's still not getting above 11.5 inches Hg vacuum. I even hooked up a pair of pumps for 12CFM capability and have the leak detector on maximum amplification. I have sealed all leaks on the bag and inside the hull over these 60 hours. Still 11.5 inches Hg (15 inches Hg with both pumps on).

    Today, I "painted" the part of this hull half that is already infused (one side is done already) with a small bit of microballoons in epoxy - a very runny, paintable coating. This is the only place a leak can be happening, even though I do not register one specifically on my leak detector. I can hear faint ghost whispers of air moving in the area with the leak detector, but there is not one leak big enough to register on the detector. So, I closed the entire area in with the runny bog, painted on.

    Tomorrow, we will see if I can get more vacuum, since the epoxy is still curing.

    My point is, in 60 hours, if I hired 3 guys to hand laminate, I could have been done with the lamination I'm currently working on, plus another hull.

    I have to wonder why it is that we infuse? :confused::confused:

    It is going much much slower and the final laminate quality is no higher than my hand lamination. I have to fill in holes in the infused glass with bog, just like I have to fill in the weave of the glass with bog when hand laminating. It doesn't appear to be saving me any time or money and doesn't appear to be creating a better laminate.

    Why do we infuse?
  2. AndrewK
    Joined: Mar 2007
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    Location: Australia

    AndrewK Senior Member

    CatBuilder, perhaps now you can understand why I recommended that you do not go down the infusion path as it is not compatible with your requirement of cheap and fast build.
    Infusion can become a curse, once you see the quality laminate it can produce its hard to stop yourself from attempting to infuse everything. You need to learn to be practical and know when to infuse, vacuum bag or hand laminate.

    So why do I use resin infusion;
    1. quality, comparing a good infused laminate and a good hand laminate is like comparing chalk and cheese.
    2. weight saving, infused laminate will have approx 50% less resin.
    3. health, exposure to resin is greatly reduced.
    4. reduce the effect of high humidity environment.
    5. can do very large laminates on your own.
    1 person likes this.
  3. Fram
    Joined: Nov 2004
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    Location: The Netherlands

    Fram Junior Member

    Sean, I don't recognize your problems. If using airtight foam, then you can make an airtight foam hull. It is as simple as that. You can make life easier by using as large as possible foam parts, reducing joints, do not screw through the foam, keep thinking ahead, treat the foam as a baby and be smart in the choice for infusion, vacuum bagging or hand-lay-up.

    When you can't get enough vacuum, then you made some mistakes in your preparations and if you cannot resolve it you have to ask yourself if this method is suitable for you.

    Infusion is not a hype, but also it is not for everyone. For me it is the fun part of my project. For you I didn't recommended it.

    I'm with AndrewK, could not say it any better.
  4. CatBuilder

    CatBuilder Previous Member

    Henny, I guess I must ask then, how long did it take to thermoform your foam, then make it completely, 100% air tight? How many days?

    I used the cake decorating bag technique to fill the gaps and they still leaked sometimes, though no gap could be seen. My balsa deck leaked, even after putting a coat of bog on it to keep it from leaking.

    Infusing a single side is a nightmare. Even infusing the "other side" does have its problems with core leakage through. Of course, I am speaking of using a single 1150g triaxial skin, not many layers of smaller glass, which is probably another reason why mine is leaking. A single layer tends to have more pin holes.

    I'm with Andrew K also. It is great sometimes and it stinks other times.

    I'm just tired of reading about how it's the best thing in the world. There is so much hype about it, you'd think we were talking aobut cold fusion. It's just another way of putting some epoxy on some dry glass. As Andrew said, it is great sometimes, not appropriate at other times.

    My thought is that it is not appropriate when you are infusing a single side of a core where you cannot get a bag all the way around the part and that part is also not on an airtight glassing table.

    I am preparing to infuse my dagger board trunks all in one shot at this time. I can get a bag inside the trunk and outside, making for a leak free, perfect infusion. This is an example of a great use for infusion. So are beams and other flat panels you can access from both sides.
  5. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

    Yah...way too much hype around Infusion.

    This is the way I do it. 100 percent succesful ...every time

    Bloody Mary Vodka Infusion

    You Will Need:
    •Mason Jar
    •Cutting Board
    •Large Knife

    •3 Large Tomatoes
    •2 Cayenne Peppers (or any chili peppers)
    •Handful of Peppercorns
    •Handful of Basil
    •Handful of Cilantro
    •A Few Shakes of Red Pepper Flakes
    •4 Cloves of Garlic
    •Good (Enough) Quality Vodka

    1.Wash everything
    2.Quarter tomatoes
    3.Place all ingredients in the jar and add vodka to cover
    4.Store out of direct sunlight for 3-5 days, give it a shake here and there
    5.Strain using a coffee filter

    Easiest thing in the world. No paper paint suite, rubber gloves, Bog, no air leaks, no cure time worries.

    Do remember to add tomato juice , a pinch of salt and serve in a chilled glass.

    Attached Files:

  6. idkfa
    Joined: Sep 2005
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    Location: Windward islands, Caribbean

    idkfa Senior Member

  7. CatBuilder

    CatBuilder Previous Member

    WOW! No kidding. Michael, that looks fantastic.
  8. Landlubber
    Joined: Jun 2007
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    Location: Brisbane

    Landlubber Senior Member

    ...thanks Micheal, so many people get easily confused eh......not only does it look nice but you can eat it!
  9. Fram
    Joined: Nov 2004
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    Location: The Netherlands

    Fram Junior Member

    Single side infusion on a foam hull (mold)

    Hi Sean, your question triggered me to look in my building log to see how many hours I've spent on this part. I've put the result in the following table. By the way, for me this was interesting enough to publish a new post in my blog.


    In the following video you can see the proces of thermoforming the foam into my port main hull half and also the effort to make the foam hull airtight.

    In the next video you can see the layup of the laminate and infusion consumables, the making of the vacuum bag and the infusion. Note I had a big leak in the bag I could not find. The next morning I asked the cleaning lady and she found the leak within a few minutes!! a 10" triangular tear, in the video at 3.59. Ladies are much more patient.

    Last edited: Dec 25, 2011
    1 person likes this.
  10. CatBuilder

    CatBuilder Previous Member

    Good post, Henny.

    Those charts look accurate to me. I think I spent a similar amount of time on most of the steps, given that a catamaran hull is in between a trimaran float and a trimaran main hull in size and complexity.

    The problem I ran into was that somehow, even with the cake bag, I had foam/bog joints that still leaked. They looked sealed from the surface of the foam, but they were not. Somehow, air still made its way up through the gaps in many areas.

    Then, that air caused a pin hole or something in my final laminate (just one layer of 1150g/34oz), which would then also leak from the other side when infusing the outside! Very frustrating and very common throughout the hull.
  11. AndrewK
    Joined: Mar 2007
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    Location: Australia

    AndrewK Senior Member

    CatBuilder; the main difference in our approaches is that I buttered the edge of the foam before pushing into place and securing. So I had a full width glue edge, there was no need to rout out and fill the joins later. The foam and glue lines were airtight as proven with infusing the inner deck laminate on my last half hull. My foam was only 16mm and the screws holding it in place penetrated approx 10mm. So I am guessing that I should have been able to infuse all of the inner laminates as well rather than the torturous hand laminating.
  12. CatBuilder

    CatBuilder Previous Member

    I don't know how you were able to do that, Andrew. My hat is off to you.

    I can't imagine juggling my heating element, a screw gun, mixing up bog and trying to get the pieces in place before the bog goes off.

    I'm thinking you must have had some special technique? You did thermoform your core, right?
  13. jim lee
    Joined: Feb 2007
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    jim lee Senior Member

    For us, its a vacuum tight female mold. We use core that's double cut and everything is infused at once. Outer skin, inner skin, core and sometimes even some structure. What I see you trying to do looks nearly impossible to me.

    -jim lee
  14. Herman
    Joined: Oct 2004
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    Location: The Netherlands

    Herman Senior Member

    I remember a private message sent to you long time ago:

    Hi Catbuilder,

    I stopped responding on your buidling thread, because I feel it is not heading into a direction which is of benefit to you.

    However, I would like to inform you that my proposal is a solution that is being used many times, among professional and DIY boatbuilders, and gives you a hull quickly.

    (Core-Cell hull, outside hand laminated, inside either by hand or infused, rest of cored laminates in PVC foam, which is a bit cheaper).

    Make sure you use not too heavyweight multiaxials when hand laminating, as you will regret that. Biax +/-45 seems to laminate easier than triax or quadrax.

    Best regards,

    Am I rubbing it in? No, that is not the purpose of this post. However, you have learnt such a lot now that you are able to make a decision on a per-part basis on which method is the best in your workshop.
    I still feel that for various reasons (simplicity, budget, time) my proposal would have been a viable option. OK, you would have needed a laminating crew of say 3-4 people for probably 2 or 3 days, but it would have given you a decent outer laminate for 2 hulls. The inner laminate can be infused then.

  15. CatBuilder

    CatBuilder Previous Member

    Herman, only trouble is the inside must be laminated first. There is no way to laminate the outside until the inside is done with these molds.

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