Hey guys,
I’ve put together a diagram detailing the basics of a Vacuum Infusion layup.
It’s a compilation of best practice learned on this site. If you have any suggestions or input/corrections, I’d appreciate hearing from you.
Thanks in advance,
DallasAB
Great! It looks like a bunch of folks took a peek at the diagram and no one screamed at me yet, so I assume the basics are covered!
I’ve seen too many ruined parts on this site - many of which come down to improper placement of fabrics. (“brake zone”, perforated film placement & etc)
For a lot of the guys doing this every day, it’s a no-brainer to be sure - but for newbies (me), it helps me to map it out on paper so I have something to refer back to.
My first infusions are scheduled for early next summer.
I’m hoping for stunning success with no ruined parts… that’s the plan anyway. (we’ll see…)
DallasAB, I am having trouble deciphering your diagram… Is this a top down schematic with layers peeled back for viewing purposes only? Also, what is the purpose of the perforated release film? I’ve never seen it used in vacuum infusion, only in wet bagging or prepreg.
Yes, the layers are shown peeled away for clarity.
It was challenging (for me anyway) to create a 2D diagram that shows what’s going with the layers.
If you can imagine a flat piece of foam being used to make something like a bulkhead.
You would start by marking out the piece and then cutting it 4" oversized.
(that’s what you see on the left side of the diagram - actual part line +4")
Then, a 1" strip of epoxy and microballoons along the extended edge to seal the foam and create a better surface for the tacky tape.
This step may be omitted…? I got it from Henny:
(Scroll down to “Starboard Float - The Beginnings”)
Click on the image below that to launch the photo album. You’ll see the purple band across the outer edge of his float.
After that, the reinforcement fabric gets placed with a 1" oversize (for trimming).
Over that goes the peel ply - this goes all the way to the vacuum tubing (which can be cut into sections allowing you to clamp off vacuum from certain areas that may infuse faster than other areas).
Next goes the Perforated Release film which allows the consumables to be easily removed from the peel ply and also controls the resin flow.
(I’m still a bit fuzzy on this layer, but Herman swears by it and from what I can tell he really seems to know what he’s talking about)
There are quite a few threads on Release film. One of which is here:
That layer ends +1" over the fiber reinforcement.
On top of that is the Resin Distribution media which ends -2" from the cut line. This serves as a “brake zone” - Again, from the reading I’ve done so far, the brake zone gives some areas of the infusion a chance to catch up with the rest of the part and allow time for a complete infusion.
The Resin Inlet tubing has Flow media both under and above it and must be touching the Release Film and Peel Ply.
Depending on your resin viscosity, shop temperature and part complexity you will want to make sure your part will infuse completely with some time left over before the resin kicks.
For the epoxy I’m looking at, the working life is just over 80 minutes at 72 degrees - so I don’t want the resin flowing after about 30 minutes.
I plan on plumbing accordingly, (zones or whatever) to shoot for a 30 minute max infusion - this gives me a bit of breathing room in case something happens.
+20 minutes pot life remaining
In the end, what I’ve tried to do here is get something on paper that I can pin up on the wall to use as a static reference.
It won’t work for all parts, I understand that - but I’m hoping it does speed up a layout and make it easier and clearer to explain to others.
I also had difficulty reading/understanding it. I saw some things that look incorrect possibly but I am unsure if its just how I am interpreting it. Doing a cross section drawing would be best to demonstrate.
OK - I’ll work on that today and post it later… that way you guys can tell me if I’m on the right path, or what I need to tweak.
OK - Here is Version #2 with a Cross Section drawn in.
Please let me know if something needs to be added/removed/replaced & etc.
Thanks in advance!
Dallas
I would remove the perforated release film. Altough you can use perforated release film between the peel ply and flow media it is unncecessary and adds to the already high cost of consumables.
You may want to show the peel ply going completely over or under the vacuum line.
I am not sure if “foam” is the ideal mold material for vacuum infusion.
Aside from removing the release film, do the spacing distances look correct?
Foam (CoreCell or Divinycell) is what is called out for a Farrier Trimaran. Possibly not the best material for Infusion, but definitely works.
See Henny’s site (linked above)
Tons of good info there.
Version #3 - Thanks for the input!
Messing around with these drawings… I think I figured out why Henny and some folks use the Perf Release film.
For their particular projects, the Peel Ply REMAINS on the part for quite some time after the infusion to serve as a protective layer while fitting bulkheads and etc. If you did not use that layer, I think you might have one heck of a time removing the bag and distribution media without causing a huge mess with the protective peel-ply layer.
Definately. On boats you want the peelply to be there as long as possible. It protects the laminate from foot trafic, spills and dropped tools.
I must also say that I almost always use perforated film, I hate removing infusion mesh together with peelply (which, unlike the name, is a bitch to peel, especially when the epoxy has had a final cure).
Nowadays I tend to use the compoflex material more and more. (wishing they would make a more drapable version as well)
One other thing to keep in mind while removing peel ply from large structures is static build up. Once the perf. film is removed, the part is sufficiently charged. What we do is to rest a piece of metal touching the surface and some part of the ground to diffuse it. It helps but doesn’t completely eliminate the static buildup.
DallasAB, you have a good stack setup there, but at the end, where you have the vacuum hose, I’ll stop the peel ply say 1" from the hose and cover the hose in a peel ply of its own, and use strips of glass rovings or stands between the two peel ply’s to create a resin front-break. That will be more effective for thinner materials when you want to prevent your resin trap to get filled up with a lot of waste resin.
why is this infusion all done on foam?
The particular project I’m planning for is a 39’ Sailing Trimaran. (F-boat.com) It is all done in 5/8" Closed Cell Foam. The project is scheduled to start next summer and run for 10-12 years. It will be a huge part-time effort scheduled to coincide with retirement and finances while allowing plenty of time for LIFE itself. So, while I’m getting things lined up to begin - I spend quite a bit of time learning as much as possible from others that have gone before me and also the gold mine of Composite information available on this site.
you are only laminating one side of the foam? or both?
Both sides are laminated - Mostly 17oz Double-Bias.
Flat panels will be infused both sides at once then cut to proper size and installed. Hull will be infused one side at at time, then joined and infused again on the outside. Henny’s site shows the general procedure on this. His site is awesome! Check it out if you get some time.
So why do you not infuse the panel on a piece of glass or metal table? applying the sealant tape to the glass/metal and using one bag, infusing both sides at the same time? Its not too conventional bagging directly to the foam on each side, though in some cases it could be necessary I suppose.
When building a boat you will have to.
First shape the foam over formers (frames), then apply the laminate on the exterior, then turn the thing over, remove the frames, and apply laminate to the inside.
I have been involved in many, many DIY boatbuilding projects, and also supplied the materials to Henny (Fram). I have no idea of your intentions on building the boat. Is it the building of the boat that brings you pleasure, or is it the sailing of the boat.
Keep in mind that building a boat yourself is in no case cheaper than buying a boat. Especially in the economical situation that we are in now. During the first stages of the build, money goes slow. Every 10.000 dollar you spend will take you weeks or months to process. Nearing the completion of the boat, money goes faster and faster. (motor, rig, sails, etc all cost lots of money, and are installed in days instead of months. Make a decent budget, and try to stick to it.
In case you just want to sail the thing I suggest erecting frames (cnced or old school saber saw, which is a bit more work, but cheap), then apply strips (bead / cove) of Core-Cell foam or PVC foam (Airex) lengthwise, using lightweight polyester glue (ATC Chemicals B33 or similar)
Sand fair using grit 36 on a longboard. (should take you no more than 2 hours per hull)
Apply outer laminate BY HAND. Hire 2 experienced laminators if you feel uncertain. Inform with boatbuilders who the people are that do a good job in your area.
In general, you can only help them by mixing resin for them, and keep things tidy. A crew of 2 should be able to do both amas in 1 day, and the main hull in 2 days.
Reason is that applying the foam like Henny did, takes a lot of time and effort, and infusing the outer laminate does not bring an awful lot in terms of weight reduction.
After putting the outer skin on, fair the hulls, and prime them. Then make cradles to sit the boat on once turned.
Turn things over, fix the boat, and infuse the inner laminate. Reason for this is that laminate thickness is less critical, and hand laminating an inner hull is a big mess.
Consider splitting the hulls left/right instead of hull/deck. But I believe Farrier already tells in his descriptions.
Thanks Hojo - that’s what I do plan on doing (for the flat panels anyway - shoot both sides at once). As for the merits of building a boat on my own and doing it over such a long period of time… it’s mostly because I have always wanted to take on a big project that would give me something back in my retirement years. Right now, I’m 43 years old and I’m looking at 20 years before retirement. The kids are growing up and leaving the house and I find myself with too much idle time on my hands. I’ve been kicking this idea around for almost ten years now - but raising six kids and taking care of landlord responsibilities plus a full-time job have mostly gotten in the way of getting started. When it comes to saving money on my own build, I do realize this will not be possible nor is it an expectation. I’m really just in it to whittle away some time doing something I consider meaningful. I will learn new skills and create something really cool that can take my wife and a few future grand kids down to the Bahama’s (or wherever) for EXTENDED vacations and time well spent. I really can’t imagine anything better than sharing my retirement with family in a way that I really can’t right now. That’s the plan anyway - lots will happen over that next 20 years. Whenever I get started, I’ll post a link to my build site. That way you guys can tell me how bad I’m screwing things up.
db