Composite (glass/foam/glass) For Beginners?

On large foam one off boats you should seriously rethink the pump, I had a large duplex IR Piston pump and a booster both.

 

Can a few more people chime in on the pump? I have one vote for "yes" and one for "no." That leaves me with uncertainty.

I am really leaning toward doing resin infusion because I don't need a lot of people. More questions, I'm afraid:

1) How do you mix your epoxy in a large batch ready for infusion?

2) How long does it take to suck the resin up and through a panel that is say...6ft (2m) wide by 45ft(13m) long? This would be my largest panel. Is this where the better pump comes in? Faster filling of the bag with resin?

3) What are some of the most common problems you can run into?

4) What labor saving tricks are there for this type of build? Keep a smooth side outward so as to avoid sanding as much? Rigging the mold in a certain way? Any tips to save time on this build method?

 

For smaller infusions your pump is OK.
For wet bagging, if you want to control the vacuum (you do want that), instead of just sitting there and watching what your pump performs (or not), buy a "Vac Reg" from Airtech. (www.airtechonline.com). This is a spring operated "controlled leak" which will level vacuum levels. But keep in mind that your pump might not like this, and will spit oil. Then either an industrial vane pump would be more suitable. The small pump you show only stops throwing oil when it reaches a quite high vacuum.

Another solution can be a vacuum switch, which kills the pump when the desired vacuum level is reached. No noise, no dollars spent on power. An example is a Danfoss RT121 (no other Danfoss switch is suitable for vacuum, in case you might ask)

Consumables for infusion:
-vacuum film 75 mu (0,003") WL5400 Airtech (or SL500, or BBL100, also Airtech)
-infusion medium (I do not like the black knitted stuff, or any of the hard meshes, they might also have another knitted mesh. I am not sure, as I have my own mesh made...)
-perforated film WL3900 P, or better WL3900 MP22, or their new stuff WL3700 P16. This is needed to get the inf. medium off the boat.
-peelply where you need it. I recommend the whole boat, if it is boats that I work on. (I do many other items that do not need peelply at all places)
-spiral wrap
-T-pieces, valves
-overflow vessels. Get some large aluminium pans, and have plexi lids made. A drill, a thread cutter (1/2") and some accessoiries get you going. I can mail a photo if you like.
-some tubing
-sealant tape.
-leak detector. A must-have.

For wetbagging the list is approx the same, change infusion mesh for bleeder, and the perforation you would like is P3 or even something with less perforation. Personally I feel wetbagging is stressful (working time of resin) but I guess I grew towards infusion. I am even working on an instruction book... (almost finished)

But do think about whether you would like to infuse. You will need an airtight layer on your foam first. Infusion of the inside, once the exterior has been hand laminated, and the boat turned over, is more easy.

Enough for now, baby crying...

 

Apart from all the attractive sides of resin infusion, let me ask a question please.

Don´t you have enough from your first experience on this project?

Shall I tell you where you can find hundreds of fµcked up hulls and decks in "resin illusion" technique?
Professional operating yards produced that scrap, not amateurs!

Forget about the pump. Use your vac cleaner to keep your shed tidy and go for a handlayup. EIther wooden strips or foam **** does not matter that much, but do it according to your skills not your phantasies!

Sorry but that was required.

Regards
Richard

 

Ha! I like that post, Richard. No apology necessary. I'm here to learn.

I understand the drawbacks to infusion (complete disaster possible).

I am not understanding the benefits and drawbacks of 100% hand layup vs. bagging. Can I just mix and match?

For instance, it might be a good idea to vacuum bag a long hull panel to save weight and produce a stronger part in one go with less stress of managing materials. Is this not accepted fact? Would I be better off just doing the planking as you say, (foam or wood)? What would be the main disadvantage to doing the planking? Sanding/fair worse?

I'm just trying to get a good grip on the various ways to do this project and also to come out with a strong, light boat, but yet save some time.

And yes... I have definitely had enough from my first experience! ha ha I need to use a manageable, repeatable, reliable technique that also produces a good, strong, light boat.

 

I should also add that this is my last chance. I have just enough money left to buy a low quality catamaran for charter. I would prefer higher quality, so I am returning to building. I will spend the money on the build, so there will be none for a low quality catamaran. This needs to go well and smoothly.

 

I regret Richard talking so negatively on resin infusion. I guess he has seen disasters made by incompetent people that refused to either start small, or buy the neccesary knowledge.

I have been involved in setting up infusion at Elan Marine (Slovenia) after another company produced a lot of garbage at Elan for almost a year. The first product they produced after my recommendations and schemes produced a boat, not garbage. Many more projects were to follow, in Europa and abroad.

There are many builders, professional and DIY that use infusion profitably. If you understand the principles and gain some experience, the possibilities are almost unlimited. However, with each project or sub-project, you should ask yourself which technique is the most suitable. This is definately not always infusion.

For Catbuilder, here is what I would do:

-set up frames, cover with foam strips. Make sure your hull will become 2" higher than the eventual product, so you have some extra room for a possible flange, if needed.
-cover with foam. (or wood. I suggest making a small panel of each beforehand, weigh it, test it.)
-hand laminate the outside. Your laminate will probably be so thin that infusion does not make sense.
-finish outside up to primer stage
-turn around

In the meantime you can do some testing with infusion (your Robinair pump should do the job fine). Make a small bulkhead, make a slightly larger one.

Now decide whether infusion is for you. If so, you can infuse the interior laminate. If not, hand laminate it. (then make sure your rolls are cut in 25" wide instead of 50". Plan on laying up all layers athwartship, the smaller width helps preventing the need to walk in wet resin. Do the topsides of a 25" section first, then the bottom, then move back a bit, and do the same.
Basic challenge is to buy the infusion materials in quantities you need.

Make sure you know your way in the steps ahead. spend some time on gaining knowledge. See if you can visit some yards, you will always learn.

 

#1 there is only one way that is to go by weight.

#2 Do a test, BTW It is not the better pump but one of the proper size and only a madman would try a 45 foot section with a 4 CFM pump a clue would be the Handle!!!!! real vacuum pumps do not have plastic handles mine weighed @900 pounds and there is one of my boosters listed in here it is 7.5 HP and 1200+ CFM

#3 That would be mainly "strategy" in the plumbing system setup,The dairy cow look results from piss poor planning.

#4 Myself I build foam core one offs and have done many panel boats as well ,that is a quick building system.

 

#1: Weight or volume, whatever works best for you. Just keep the required mixing ratios as per the datasheet (they are different for weight or volume).

Make sure you have a powerdril and a good mixer ready. The spiral ones work OK, although they mix in quite some air. A dissolver disc would be an option as well. Preferably your mixing bucket (plastering wholesaler) should be white. If your hardener is tinted, so much the better, as it is easier to determine if the mix is OK.

You generally do not need to mix very large quantities. The last project I did consisted of 11 batches of 16 kgs (approx 35 lbs) each. We premade 6 batches, the rest we did as we went. We made sure we kept the additives (it was polyester) ready. The resin was decanted from the barrel as we went. We had the luxury that one of the guys was dedicates to just do that.

#2. Your pump might work, but it is small for that. Everything depends on leak control. Get a leak detector, do a drop test. If not OK, chase leaks. Check everything. If you develop a leak somewhere, a larger pump is no luxury. Plastic handles or not, I do not care. I have a large pump with plastic handle, and it still does a great job, even on 30 ft boats. If you need 900 lbs pumps and 7.5 HP, then there is something wrong.

#3. Common problems: Infuse while there is a leak somewhere, leak in bag, leak in mould (specifically if your mould is the foam structure without laminate, or one layer of laminate), strategy in general, strategy spoilt by race tracking. many things can be solved during the infusion, although they do require some planning.

#4. Good workplace, enough room, keep things clean, be accurate, a leak detector. All things that cost more time beforehand, but save time afterwards.

 

That Big Ingersol rand pump ran my entire shop, what is wrong is You recommending 4 CFM for a 14 meter Job over foam core are you nuts???.Problems arise from using toy pumps with no reserve capacity and 15K in material on the line.

 

MANAGEABLE

that was the right term.

The panel bagging again requires helpers, you can not manage a 14 meter panel layup alone.
Then you have the big sheet of wobbly stuff, need assistance again.
All your tooling is extra cost and extra time to be build (and wasted).
Counting all, I am in doubt, that the one sheet (4 actually) method saves any time in a one off project. But the chance to come out above budget, I can see with ease.

A strip planked hull can be done easily by yourself, and according to YOUR pace, not the resins pot life.
These are slender hulls, you must not use scaffolding or hughe ladders, so, you can reach to every part of the hull without assistance.
The method is idiot proof (even I can do it), and has a low potential to be screwed up.
The pace is rather fast.

Using bead and cove lets you skimp on fasteners plank to plank. (given you still work with Epoxy)
Going wood instead of foam would save you some money, even when you have to import KIRI timber. In that case you would save weight over the foam core also!

The question is, if your design allows for strip planking?

Regards
Richard

edited:

while I was distracted from typing (I am sailing), several new posts appeared.

Herman is a very valuable source of knowledge in this field, and you can absolutely be sure that his advice is sound and proven! Though I would agree with the "loudspeaker" that your pump is a bit tiny. But if the flat panel layup is the method you choose in the end, I do not see any reason to invest in a really professional pump. On a flat table you have it easy to avoid any leak.

Herman,

Elan was one example I had in mind with my former post. The entire French boatbuilding scene the other! All the yards in France have contributed to the local landfill for years and years. (but to whom am I telling that)

Regards
Richard

 

Ok, I am seeing some agreement here among the posts.

I see that I have at least 2 votes for doing a male mold/jig and doing a layup on that by hand. This is encouraging.

Let me read a bit more before making a proper response. I didn't realize my layup would be very thin on the outside of the foam hull. I had thought with foam you needed a lot of extra glass/epoxy to get the strength. So many conflicting things to read...

Thank you for all the help here. I have to consider these posts a little bit...

 

The point of a core is to use less fiberglass for the same stiffness. If you're comparing foam core vs. wood core of the same thickness then yes, you do need a lot more fiberglass over the foam because wood is strong and foam isn't. But you'll still need less than if it was solid fiberglass.

 

Yes, I should have been more clear. I was comparing to the other build process I had started, which was a plywood boat with glass/epoxy outside.

 

My testing indicates different much different.the super foam cores fare well and the wood fails instantly along with the cross linked foam.

http://www.youtube.com/watch?v=DRzyw0Jo8Zg