Resin infusion

Hi there,

I am a amateur boatbuilder or better said I will be one within the next few months.

Designed my boat from scratch LOA 7.42m, beam 2.84m daycruiser ,...

As I went more into research I ran into Resin Infusion techniques. I was wondering if it can be done by an amateur?

It would have the advantage of having the time to layup all the glass into place
without having to rush for the limited potlife.

Any comment is welcome.

Greetings,

Daniel Peeters

 

check out this guy in the Netherlands...

http://www.fram.nl/workshop/controlled_vacuum_infusion/cvi.htm

 

Yes, can be done. To keep things simple, you need a plastic bag and a vacuum cleaner and your there!

I believe the the Gougeon Brothers cover this subject in their book: "The Gougeon Brothers on Boat Construction".

That's a mistake!! You still have the potlife, as soon as you mix the resin with the accelerator/hardener. And before you go infusing a large object to have to make some tests, because you want to be sure you have enough viscosity during the whole infusion process. Because with this process you can't stop once you started.

Give a call to Conyplex in Medemblik (Netherlands) or more local, Etap, maybe you can get a tour in their factory?? You could learn and discuss!


Good luck.

 

Maybe here's also some good info:

http://www.marinecomposites.com/Chapter_1A.htm

And see this thread: http://boatdesign.net/forums/showthread.php?t=4616

 

regarding infusion

regarding infusion:

This is not correct. You cannot successfully do infusion with just a vacuum cleaner and a plastic bag.

Firstly, a vucuum of near 30" is a must so that deletes the vacuum cleaner. And any air introduced into the part during the infusion will create a bad part so that deletes just any plastic bag.

Go here for partial insight into what it takes:
http://www.grpguru.com/vipupdate.asp

 

Vanbokklen,

You're absolutely right, but I meant "the vacuum cleaner and plastic bag" as for describing the process as easy as possible!

 

Damn, now I did by a brand new one and you tell me that it won't work?
And I didn't find a bag that would fit around it neither.....


Just kidding LOL

I was already that far knowing what Dutch P was willing to explain

But besides the documents you find on the internet, does any of you think it is cost/time/quality worthy for an one timer (maybe more if it goes well)?

Greetz

Daniel Peeters

PS question for Dutch Peter, do you know some company selling Z(stern)drives for good price in Holland?

THX

 

Lucky me!!!!

Yes, I think it's time efficient = you do the impregnation in one time instead of in 4 times (?) when doing hand lay-up. Preparation is about the same, I estimate.

Quality, when done right, the quality is better then with hand lay-up.

Cost: I think infusion is a bit more expensive, depends on how you look at it! Think of it this way. Your saving money on your health plan, as you're not inhaling toxic fumes!!!

I'll ask around!!!

 

VARIM or vacuum assisted resin infusion method

Daniel,

The supplier of all needed materials AND advise in Holland would be Brands Composites www.brandscomposiet.nl ; ask for Herman Brouwer sr.
We have been working with them since our first infusion try out in 1997. It's working allright, but be very very careful creating enough (near)vacuum ...0.6 to 0.8 bar will take care of infusion, but no less. And use special injection resins and catalysts. You do not need a quick setting process, once the work is done ... go asleep and come back next day. Your vacuumpump will do its work (if you have put an overfill-reservoir before the pump .... you will always infuse a little more resin than needed and this spill should not run into your pump !)
Brands Composites also have a hot spray that sets very quickly for lightly glueing different layers of glass to each other, thus avoiding the problem of having the layers shifting out of place when your working on putting the package in place.

And whatever people advise ... do not try to infuse two sides of a sandwich in one go. The succesrate is far lower and not to be tried by a firsttimer. It will simply take some investment and trials to get the double stuff going.

If you want to be really sure that your not going to have to throw away a badly finished product: go for handlay up with slow setting resins and apply vacuum techniques after laminating. Brands Composites can tell you all about curing times etc. Tell them I sent you.

Good luck
Lucas Adriaanse
Fasttrack Yachts - NL
(our latest one off: www.corby347.nl)

Voor uitgebreide bouwreportage met 100-en foto's: www.jlba.nl in Nederlands

 

The Gougeon Brother book on boat construction does not speak a single word about resin infusion. All hand made wood and epoxy resin.

A part the fact that probably the futur builder is not a highly skilled boat builder broken to the fabrication of composites, the price of the tooling and consumables for making just ONE small boat is irrationally dispendious...we can dream also of an air conditioned and humidity controlled shop, vacuum pumps controller by computer, high tech metering units for the resin and a little 40 feet oven with electronic thermostat....

For just a SINGLE simple small boat it's too much technics compared to the small strength gain and the very big risk of mess with loss of costly materials. Complicated technics are useful only when you truly need them, otherwise it'is pure gadget.

I would stay with brushes, rollers and a lot of careful work...although I have used all that tooling for big race multihulls paid by sponsors with millions of dollars, so I know what it is in true life...

For a shipyard it's a very different thing and resin infusion is an excellent method, when well mastered.

I would rather spend this money for the best diesel engine, a 2 speed gearbox, a perfectly matched propeller, nice fittings and for all these delicious luxuries that make a boat so expensive.

 

Ilan Voyager,
I agree with you on the risk a firsttimer would be taking. However, computer controlled pumps and airconditioned surroundings etc. is a little far fetched. We have done plenty of good jobs with just an average size pump under normal conditions, without autoclave or oven. Some other builders in Holland have done likewise, with great succes. However, hand lay up + applying vacuum thereafter is much safer to start with. Then, later take it one step further, infusing small panels to start with.
Using VARIM techniques for carbon UD's is even more difficult.

So Daniel, the sincere advise is, if you want to investigate into the infusion world: borrow an adequate vacuumpump, buy the right bleeders and rovings, and just try a small panel for starters. But don't hope this will save you money or time in the beginning.

Lucas

 

Lucas, I agree with your post. My own post did not retired any merit to the method of infusion which is very good althought having some complexity and permits to get very well done composites by the control of the ratio fiber/resin and the degazing. I would say that it's a semi industrial method.

The method is primarily adapted for a ship yard which will amortize the investment in tooling, material and learning step. As I remember the tooling and a reliable vacuum pump (it won't work with a modified fridge compressor as for old vacuum hand layed) are not truly cheap for an amateur. The basic investment may represent a big percentage of the materials of a simple 7.5 m bare hull and will permit just to make the flat pieces.

The infusion is also well adapted to insure a good impregnation with fibers hard to wet. An avanced home builder may have interest also to use it specially if making a racing boat like a Mini Trasat 6.50 where weight savings and high quality are primordial.

For the hull itself the infusion method needs good strong molds unaffordable for the amateur building just one hull.

Mastering this technique for big pieces is not easy. The shipyard Tecimar who was one of the pioneers of this method, had big problems and costly failures before getting the experience needed to go to hulls. After, this shipyard was able to make a 39 meters boat like Vendredi 13.

I wanted just to point the fact que for a first timer working on his first project which is a simple small and surely cheap boat (to start with a small day boat is a very wise decision from him), it's better to begin by the very beginning, which is to learn and master the technique of hand layed glass composite. When well mastered the results are far from ridiculous.

It seems useless to me that an amateur (a nice term, it means in french: who loves something) at his first project starts with an investment of material out of proportion with the budget of his small boat. After the first one, if he is interested by building another boat more ambitious and better built, the infusion method will be worth.

So the dream description was a ironic one and voluntarily exagerated about technique and costl escalade.

I think that the task of this forum is a sharing of knowledge and experience. I've learnt a lot here. But even if you are considered as an old "emmerdeur", it's good (and I feel better after) for example to warn, specially about temptation of using bad materials as polystirene foams or improbable projects out of reach of a (poor) amateur.

Most of us have "shoestring" budgets and big dreams; it's a good service from those having experience of a field to give advices which may save somebody a too costly failure in all fields, as well as personal than monetary.

 

Another option

I have NOT used this... But acording to SP Systems their Sprint Prepreg is easy to handle and would probably be easier to manage than a resin infusion system, still need to vaccuum and cook though...

When (if) I have the possibility of making my dream oneoff, I'd use Sprint if I could afford it.

Sure the material as such is expensive but learning to setup and use an infusionsystem is not cheap either.
For true series production I would say infusion is more cost effective.

 

We are very far from the subject of the thread...but I do not resist to the temptation to give a short information about prepegs.

Infusion is for shipyards using polyester and it's very cost effective in small series.

Preimpregnated fibers are UD or clothes impregnated with a high modulus epoxy resin which needs high temps for curing. The prepegs are stored in freezers so the resin won't cure. It's a very highly technical product but may be used by an amateur in some applications.

Prepeg has two sides;

1/ The Pro side for building high tech boats; you have plenty of time for putting the layers in the mold as the resin won't cure until cooked. The vacuum is applied and the oven is heated following a very strict schedule for the temperatures: a/the resin liquefies and degazes by the applied vacuum, all eventual excess resin is drained out b/the polymerisation begins c/ the post cure applying a higher temp d/ the cooling a crucial stage where the internal tensions must be released. Some prepegs need 2 days in the oven...

The shipyard Multiplast has a oven of 50 m (about 165 feet) able to cook a complete hull or a mast. The cost is very high but the quality meets the highest standards. The ratio fibers/resins is incredible.

2/ The amateur side: a good amateur with simple means (fridge compressor used as vacuum pump, home made oven, freezer etc) and great care can make very high tech foils and hardware.

The lone problem is to find prepegs at retail, the price is high (in 1989 about 100 US$ a pound of carbon prepeg).

 

[QUOTE=lucas

And whatever people advise ... do not try to infuse two sides of a sandwich in one go. The succesrate is far lower and not to be tried by a firsttimer. It will simply take some investment and trials to get the double stuff going.

Lucas....are you making this suggestion for beginning infusers only?--or do you find this an ongoing rule?Certainly ,as eloquent as resin infusion process is for overall production,,it seems the learning curve to successful infusion ,,and potential gains are questionable for 1 timers!
Have you developed any strategies to reduce the resin weight from the resin which fills the 'slices",in contour foam?or is the added structural stability worth the weight(if the goal is top end strength/weight ratios)??