Is there a general rule for the number/size of pleats to put in a bag? I’ll be infusing mostly flat panels max 22" X 42". Nothing fancy just deck hatches etc. Should I put two pleats on the long sides and one on the short? About 3" high? Just guessing now but a few hints would be appreciated. It appears from my first tests that pleats seem to be the key to getting that elusive perfect seal on a layup. Thnx.
I thought pleats were mainly for height changes, if your panel is flat I wouldn’t see a need for it?
You dont, and your right. Pleats help to keep the bag from bridging.
As many as needed so the bag doesn’t bridge or tear open!!! 
Right now, I’m doing flat panels, and have at least 2 on each corner (each side), and 2 more along the infusion inlet/vent sides, so nothing gets too tight around the tubes.
they are all about 2" high. Total part height is .375", and another .5" for the tubes.
closer to acheiving that perfect seal! 
Well maybe not perfect but better. This is a test stack, dry, to help refine my technique before I actually risk some foam, epoxy & glass (maybe tomorrow). This time I got the bag to hold a vacuum which is cool. Still not enough pleats I think. There were some areas where bridging was till evident.
nice nice. I could think that you would want pleats (on each side, equally) where the parts are separated. That way the extra bagging will go down onto the lower surfaces.
Ok I got this one wrong. I should have put the inlet lines on the long side. It’s an odd shaped panel. Anyhow, have a look you experts. Any suggestions are greatfully appreciated. I’ll have a crack at the other side after I get some feedback. It’ll be another 20 hrs or so before I unmold this one.
I used the white flow media Werks sent me. It appears to work ok but then again I’ve never done this before.
firstinfusion001.jpg is the stack layed up ready to pull the vacuum.
firstinfusion002.jpg is the stack with vacuum pulled.
firstinfusion003.jpg is after about 11 mins of infusion and the resin has already reached the vacuum outlet by running up the sides. I should have stopped the flow media and not allowed it to drape over the edge.
firstinfusion004.jpg is after the part fully infused at about 32 minutes.
So you draped flow media over the entire part?
How was it wrong if the panel was fully infused? Sounds like a success to me!
And those panels are not what I would call “flat”
. What kinda surface are you working on, a door?
I used the flow media on both sides and covered the entire part. Had it been a square or rectangle I probably wouldn’t have done that.
Well partial failure. I learned some things. That’s primarily what it was about. The resin flowing around the part was extremely problematic. It filled the resin trap (which was too small to begin with) and the exit line. After the resin kicked in the lines I lost vacuum to the stack and the edges lifted.
The part was/is intended to be half of a set of covers for our sump pump well! Excitin’ huh? I just wanted something to practice on.
The tooling surface was a 2x4’ piece of malamine. I waxed the crap out of it (probably 10 coats). It held up well, I might be able to salvage it.
I pulled it apart this morning. The part came out with some tuggin’ and pullin’. The edges have lifted but I’ll trim those. The layup worked extremely well considering there were two layers of 1708, top and bottom.
The ULV resin from Polymer Products seems to work as advertised. A little slow for small parts production. The Flow Media that I got from Werks seems to do it’s job. It’s a pretty fine weave and maybe more suitable for smaller parts. I wouldn’t want to use something that fine on a 30’ boat hull.
Digital camera needs batteries. Will post a pic later.
So, this fine Nylon netting that I sent you removed OK for you?
It is some Nylon netting roll that I had laying around here and wondered if it would work at all. Probabally just use it on the top next time too.
I was thinking it would / might work for small parts too.
Thank you and still one of the mods will be trying it too. I might still send him some shade tree netting to use to maybe in a side by side comparision with the HIGH Tech stuff too. A resin race…?
With a few good pulls it came off. It did stick to the tool surface, probably not enough wax or agressive epoxy.
I wasn’t sure if the resin would flow across the bottom of the stack without it. From the looks of the part now that it’s off the mold it worked just fine. If I had used glass as a tool surface I might have left it out.
I think it’d work well for smaller parts.
I’ve seen that somewhere in a video. If you’re working with quicker curing resins it’d be good info to know.
The peel ply you sent is fantastic!
Rick
Forgot I had the Nikon D90 at home.
DSC_0136.JPG Shows the front of the piece.
DSC_0137.JPG Backside of the piece.
DSC_0141.JPG No voids. Some minor delamination around the edges due to the lack of vacuum as the epoxy kicked. Otherwise it’s bonded well both sides.
First of all this process is a little labor intensive and probably not much economical benefit for one-off parts production. The benefit is your hands never touch the epoxy! The process is also wasteful. There are a lot of consumables involved, the resin flow media, peel ply, bag, spiral wrap, t-fittings, the butyl tape and the bag. I also wasted 25’ of plastic line (forgot to cut it shorter) and a small resin trap I tried (too small).
The tooling surface is a 2x4’ piece of malamine. 10 coats of release wax later you test it for adhesion with a piece of masking tape. If it sticks at all, more wax. This was the first time for this piece so I gave it a couple extra coats. There are other mold release agents available but I didn’t try them.
It is vital to ensure that your layup will maintain a perfect vacuum after you shut off the pump. The clamping pressure is what maintains the ultimate shape of the part you’re trying to produce. I’ll explain later on what happens when you don’t.
The location of your resin inlets and vacuum outlets are also critical to the success of the part. Seen here the panel is not infusing well. The resin was able to circumnavigate the part and reach the vacuum outlet too soon. This meant either pumping a lot more resin in (as I now know is wrong) or stopping the process and adjusting the flow media etc. (which is an extremely messy proposition.
I eventually got the entire part infused after about 32 minutes. About twice as long as it should have taken and using twice as much epoxy as required.
The epoxy I used is specially formulated for resin infusion. It has an ultra low viscosity and a very long working time (+5 hrs). For small parts like this the longer working time is more of a PITA than a benefit.
The completed part came out of the stack fairly easily. The peel ply did it’s job perfectly. The resin flow media (nylon screen mesh) did stick to the tooling surface. There are some areas along the edges of the part that didn’t stick due to loosing vacuum on the stack. What happened is the excess resin that was being pulled off the part kicked off in the vacuum line just ahead of the resin trap. This in essence shut off the vacuum to the stack. After that there was no way to get the whole layup back under vacuum. I had planned to trim the edges anyways.
Frontside
Backside
The larger flat surfaces of the part are perfectly infused. There are absolutely no bubbles or areas where there shows any resin starvation or delamination. Both sides of the part were infused at the same time and I was a little worried about the backside (laying on the tooling surface) not getting resin. No worries there. The flow media looks after that.
The biaxial fabric is 1708. Amazing product! A little awkward to handle such heavy fabrics and it takes some getting used to. A little 3M Super77 adhesive was req’d to keep things from moving around too much when setting up the stack. The peel ply a fine weave nylon fabric left a very smooth surface. It would probably need some light sanding for a secondary bond. I’m just guessing until I cut into the part but I figure there’s 40% resin and 60% fabric. Maybe a little less resin but not much.
So the things I learned are:
Proper location of the resin inlet and vacuum outlets are critical. Experience necessary I think so that you can judge when/how the resin will reach the outlet AFTER the part is fully infused (Ideally).
Having a perfect vacuum seal on the layup is also critical to the complete success of the final part. Any leak, no matter how small is unacceptible. An ultrasonic leak detector, such as those used in the refrigeration repair industry would be a big benefit.
A bigger resin trap is required. Mine was only about 5 oz, sort of an inline filter thingy. I have my eye on an old paint pot at the local flea market that’ll work. Shorten your vacuum lines so you don’t waste them if you suck in some resin.
Heat lamps and hair dryers are good to help control the flow of resin. As soon as the part is fully infused we lit the exit area with lamps to help the resin kick off quicker. This helped a little bit in restricting the flow of resin, as it will with a sustained vacuum applied. Downside is it prevented us from reapplying vacuum when we needed it. Two vacuum outlets, a primary and a backup is maybe a good idea.
I’ll probably do the other half next week. Need to acquire a few more materials. Hopefully it’ll go better. Will post the results as well.
I’m thinking all this tinkering with this process might lead to being able to produce some smaller parts for our project, hatch covers, etc. We’ll see. I don’t think I have the stones to try this on the whole hull of a TW28!!! That’s risky beyond belief (for me anyways). I’ve seen it done on the Internet but without professional guidance I don’t think I’d even attempt it (feel free to remind me of that)!
Thank you for a great write up!
Learn from your experiences and try not to repeat your mistakes was always my credo in the former classroom.
Also with VIP, make sure your resin doesn’t have mixing air bubbles before sucking it into the laminate.
Another tip, chart the shortest travel for the resin to travel in the bag.
I’ll have to scroll back up and read the entire thread. This is good stuff, i never thought about doing a dry run, testing the bag fit, etc.
I have a long way to go before i can produce nice parts.
When they tell you that all foams (for core) are not created equal you better listen. I cut the parts to fit the pump and outlet. Here’s what I found.
The part looks ok. There looks to be a really good resin to glass ratio. No voids. Then on the second part this is what happened with the jig saw.
The foam was completely bonded to the glass/epoxy. The foam itself failed. I’m guessing that’s what they mean when they look at the various factors, sheer modulus, etc. when they describe foam qualities.
The infusion epoxy is still a bit soft (stretchy) but is getting harder all the time. Mfgr said up to 2 weeks before it’s fully hardened. You can post-cure (heat it up) to expedite the curing process. I might try that next time because this epoxy has an extremely long working time (+5 hrs) and +24 hrs to demolding the part.
The 1708 glass/epoxy ended up almost exactly 1/32 of an inch thick! Somehow I thought it would have been thicker but due to the vacuum clamping it’s been compressed quite substantially.
Stay tuned!
Leran and share from your experiences! 
That foam being blue, is it PS (Polysytrene) or PUR (Polyurethane)? PS bad for most use. PUR is more expensive, but you get what you pay for.
Resins are like arcylic and super glues…they get stronger over time! Some take 24 to 1 week to fully cure and increase strength.
[QUOTE=Werksberg;14574]
That foam being blue, is it PS (Polysytrene) or PUR (Polyurethane)? PS bad for most use. PUR is more expensive, but you get what you pay for.[QUOTE]
Polystyrene (Cladmate Trade Name). Wanted cheap for tests. Not a structural component.
I tore apart my old resin trap which was (as I now know) Waaaaaaaay too small! lol
Second pic is new trap. Won’t be fillin’ that up anytime soon. It has a clean out on the bottom and is 100% PVC and the epoxy doesn’t stick to it. I figure I’d have to pull at least a couple of gallons of epoxy into it before it’d ever get close to the pump. The black pipe in the upper left of the second pic is just a vacuum reservoir. It’s ABS pipe. I would have bought a vacuum pot from Airtech but couldn’t justify the cost. I figure I have about $12 in the trap I made.
Now that I’m partly awake…
You will also need to “score” or scribe some extra lines in the foam for resin channels. And poke or drill some thru holes for the resin to rivet / hold the surfaces together too.
You are a wise man, practice and test before making the real product!
Thanks for testing the Nylon netting (flow media) I threw in with your eBay order as a bonus gift! I do add bonus items in every eBay or on here item with (while supplies last…) my former classroom handouts too unless a single piece of FG or Peel Ply.
And I thank you for the gift. It was only this week I discovered a use for the shrink tape. I intend to make the “shaft log” (hollow f/g tube) for our boat. The shrink tape is supposedly useful for creating tubes. I assume there are plenty of other uses.
The flow media worked well. The tight weave is probably more suited to smaller parts. I need to get some other types to try as well. I have the designer of our boat sending me samples of different foam cores to test with the infusion technique.
Cheers & thnx again.