Infusion Q&A

herman,

I want to start infusing a whole heap of flat panels on a large melamine table for my next project... i want to infuse both sides of the sandwich at the same time in one shot using a fishbone resin feeder system from the center of each panel and perimeter vacuum... the laminate is 750gr triax with 200gr woven on the table side and 600gr dbl bias on the peelply side... what is the best core material to use so that i will have least problems with uneven resin flow speed esp on the underside against the table?

 

grooved and perforated.

You could opt for perimeter-to-center infusion, which is 4 times as fast, if need arises.

Be aware of race tracking through core seams and the perimeter of the core. Sometimes it is best to accept racetracking, and design the strategy incorporating these runners (add spiral to these spots, you cannot rely on racetracking to happen)

 

And why not metal staples? I've heard of people using Raptor composite staples to hold dry laminates together before infusion. Why not cheap, stainless steel staples?

Seems as though they would be better than using any type of spray adhesive.

Thoughts?

 

Staples? For what? Flat sheets do not need staples, glue or anything. If your materials go everywhere, then shut the door or do not work during hurricanes...

As for Raptor vs Stainless. Raptor ones can be sanded...

 

For hulls, which are vertical pieces. This is not flat table Kellsall infusion, but whole hull infusion.

I see... so the metal has a small chance of sticking out of the laminate, causing a lot of grief? That is why people don't use them?

 

Some comments on previous posts

Airtight foam hull:
The first time that I met Herman we discussed my infusion plans. "Just add a 200gm layer otherwise you cannot get the foam hull airtight", that's the way to do it Herman said. Of course he was right, but this made no sense to me as the total inside laminate thickness of my hulls is only 600gm . I had zero experience with hand laminating and wanted to infuse everything to compensate for my lack of hand laminating skills. Making the foam hull airtight means having as less joints between the foam strips as possible. Here was my designer (Ian Farrier) of help introducing the vertical foam method, instead of the fore and aft strips, reducing the length of the joints from several kilometers (I guess) to about 60 meters or so. Some extra attention to these joints did the job, as well as a meticulous work method to prevent puncturing the foam (with too long screws etc.) And where it accidentally happened immediatly marked it for digging out and fill it with bog later on. At the end it was a great succes (a challenge yes but not much extra work as Herman suggested)

My vacuum integrity has always been perfect. Nowadays I'm blessed with a prof vacuum pump system (by Vacmobiles) but all my earlier infusions, also the 40' hulls, were done with a small 1.3 cfm pump. No failures, no wasted parts. I use 15 mm. CoreCell and that works well, however it seems that any thinner will make vacuum integrity a tricky challenge.

Joining hulls down the center: is not odd On the contrary, it is very logical and not only for multihull building. As we all know good joints are often stronger than the surrounding parts and the centre of keel and deck is exactly the place where you want to have this extra strength. By the way, in my boat only some extra material (tape) is used on the inside of this joint, as the outside is covered by the normal laminate and infused in one shot. In the classic way of boatbuilding there is often a always leaking joint where deck and hull meet each other.

Male or female mould: with half hulls no question. Making an airtight foam hull is easier in the female way I think. With a male mould you have to crawl inside the cramped space of the hull. In the female mould you can install all bulkheads and interior parts prior to releasing the hull from the mould, making it much more rigid. For infusing (the foam mould) it doesn't matter.

Hi Herman, no, progress was bad lately and yes, next infusion soon to be expected Came back from holidays last night but still have vacation till August 22 so hope to have some dedicated building days left.

Henny

 

Staples

Hi Catbuilder, so you changed your mind. Good to see you're converted to infusion, but beware, I doubt if this will speed up your progress. With infusion the devil is in the details and this takes time to understand. Don't underestimate this and don't do this without extensive testing of the materials of your choice or with the help of someone with infusion experience.

Regarding your staple question. You are spending multi $$$ and time, don't save a few $ on these details. If your paintwork falls off due to corroding staples you will pull your hair out.

just my 2cts

Henny

 

Good to see you here, Henny.

I am already infusing and it is very simple. I have had no problems and have infused a large part of my rudders already. Not even a single part went bad, since I started with some very small ones. I also went and infused the hull of a sistership of the one I'm currently building, so I know where to put all the plumbing. It's very easy if you buy the right materials. Which brings me to your last comment.

Is that the reason nobody uses metal staples? They may stick out of the epoxy and cause problems? In that case, I would like to find some alternative way to keep glass in place. I am not convinced about the spray adhesives. I was looking at staples not to save money, but to find a better alternative to spray adhesives.

The parts I have just done (8 layers of glass and done on two sides) were each done in a couple hours. Infusion is much *much* faster than hand layup, as there is no sanding required. The parts also came out perfect, with no weave to fill in with bog. Also, I was not even a little tired and can work 12 hour days with ease when infusing. Hand layup would knock you out with exhaustion racing against the epoxy.

I can't say enough about how much better infusion is compared to hand layup. I am really enjoying boat building now that I am infusing.

 

I don't come here very often, only so once in a while and scan for some interesting things. Before you know it, following all these forums can turn into a day job. No time for that.

I can only say: beware, the devil is in the details. However not insuperable, learning by doing. Consulting a pro is a fast way in this regard.

Yes or no sticking out is not the problem. Eventuallly the steel will corrode and expand. Something has to give.

I'm not a fan of spray adhesive either, at least with epoxy. And knowing myself, I will use too much of the stuff. An alternative method can be sewing. Your hull is upside down. First layer over the keel is being hold down by gravity. Next layer can be sewed to this one, and so on.

I found a normal office stapler usefull for fixing peelply, release film and flow fabric, also together with some masking tape. Watch out for puncturing the bag with these staples.

Henny

 

Sewing! Brilliant!!

 

Herman,
With regard to infusing perimeter to center- this makes sense to speed things up but How do I setup the vac line in the center of the panel so that the resin front doesnt have to travel a great distance? The panels are rectangular 10m x 1.8m... So a central strip vac line the resin needs to travel 900mm?

Also, would you still need flow media on top?

 

Grouper: If you will allow, I'd like to try out my new knowledge here and see if I have the right answer.

My understanding is that you would run Enka resin channels across that 900mm space from the supply line to the vac line. You would space them accordingly so there was not an overall great distance between them. A good distance might be about 500mm between each Enka channel.

Herman will be the judge of if I am correct or not.

 

Perimeter feed will speed things up but there are disadvantages as well.
Any air leaks will be pulled into the centre of the job.
If you have out-gassing then vacuum line on the job makes this worse.

For a rectangular panel 1.8m wide I prefer a centre feed and vacuum lines at each end for the above reasons. Resin travel is 900mm same as perimeter feed.
Yes you do need flow media for this distance.
If extra weight is not a concern then the grooved foam is quicker to set up, faster to infuse in most cases and cheaper.

 

I haven't used these myself but they would seem to be perfect for holding glass in unusual positions when needed.

http://www.raptornails.com/

No worry about corrosion.

 

More Infusion Q, less A.

I have a hull in a form/mold and I am going to infuse the part that I can reach while it's in the mold (see pictures).

One thought is to run a vac line down the highest point of the hull half and resin feed tubes along the bilge of the boat and along the centerline of the boat's deck.

If I did this, how do I account for the big missing section? (see photos)

I am thinking the flow would be uneven because the deck has a much *much* smaller surface area than the bilge to topsides does, since an enormous part of it is missing for the bridgedeck connection.

Any thoughts on a good plan for infusing this, taking the big missing section into account?