So I’ve been building and glassing surfboards for 10 years. I only ever did hand lay ups with poly until last year. I bit off a little more than I was ready to chew, had mixed success, and now I’m obsessed with dialing it in.

the first board I attempted an infusion on went ok. I did a hand layup of carbon on the rails to prevent warping of the board in a bag. I then used spray adhesive to dry layup 2 oz E cloth, 2mm soric lrc, and 4 oz E cloth on top, peel ply on top and infusion mesh on the rails where there was no soric. I did this for both sides of the board and threw it in a bag, pulled vacuum and infused. It worked, but I wasted an absurd amount of epoxy because of where I placed my intake and vacuum lines. They were both dead center on the board, one on the deck and one on the bottom, with spiral tubing essentially connecting them together. It made for a highway of epoxy to the vacuum line. In hindsight I don’t know what I was thinking, and I’m shocked it infused fully. It turned out ok minus the indentations from the hose lines on the deck and bottom. Lessons learned. 

The second one was a total failure. I did the same lay up, but put infusion mesh across the entire board. It infused quickly like I was hoping, but I also made dumb decision #2 and used a cheap peel ply. I couldn’t get it off and resorted to sanding away the infusion mesh and the peel ply. After a few hours of frustration I decided to take the loss and threw it in a dumpster. 

#3 actually went pretty good, the only problems were excessive epoxy waste due to the whole board being covered in peel ply, and the 2mm difference in where the soric meets the rails cause for sanding issues if i dont build up the rails with a thick sanding coat afterwards. (I will be recessing the entire deck and bottom by 2mm on the next ones to fit the soric.)

all of that is just a history for where I’m at right now.  I’m getting ready to do 3 more of these, and have a few questions for you guys with much more infusion experience than me.

#1. I hate peel ply. Do I need to use it? I have soric running through the majority of the board. I want to put a minimal amount of peel ply along the rails (edges of the board for non surfers) where there is no soric, with some infusion mesh on top of that. If i don’t use the peel ply, will i have an excessive amount of epoxy? Over saturation?

#2. The vacuum line and resin intake lines. Both sides of the board get infused at the same time. My infusion core covers the whole deck and bottom, but the rails (edges) dont have soric on them because it can’t conform to the shape. As i said above, there will be some peel ply and infusion mesh in those areas, but could i get away with only doing it on the side of my intake? Ill add an illustration of what i want to do for clarification.

1. You don't 'need' peel ply. In infusion, it has nothing to do with the resin content of your component (that's a wet layup thing), and is purely used as a release film or to get the textured surface finish either for aesthetics or for secondary bonding. Because you are using Soric, you dont 'need' a release film except anywhere you are using flow mesh, HOWEVER - I would not recommend ditching the release film entirely. The surface finish you get when in direct contact with the bag is very poor, the wrinkles in the bag leave razor sharp bits of resin that need to be sanded off. You could use a perforated release film (a highly perforated one suited to infusion) instead of the peel ply, which being a plastic are typically easier to remove post-infusion. Personally, I prefer peel ply, but I only use PA66 peel ply which is the aerospace grade stuff with the red stripe. It is significantly easier to remove than cheaper stuff, and it does its job well. Peel ply is also much easier to remove if you cut it into strips (AFTER the infusion, NOT when you are laying it up) and peel it off strip by strip, rather than trying to peel it off as one big sheet. 

2. Yes, you could. However, I would suggest losing the spiral tubing on the vacuum side, you dont  end this. Feed the resin in through a spiral with a port right in the middle to distribute it evenly along the length of the board, and then it will flow fairly evenly across the width of the board, you dont need the spiral on the vacuum side. On the vacuum side I would just have a single port in the middle of the board with a decent size (around 2" should do) brake zone to allow the rest of the board to fully infuse before the resin reaches the vacuum port and starts to be evacuated.

Alternatively, if you do want to use spiral on the vacuum side, I would recommend using MTI hose here instead so that you dont waste resin.

+x

 

Hanaldo - 5/11/2021 10:08:04 AM

1. You don't 'need' peel ply. In infusion, it has nothing to do with the resin content of your component (that's a wet layup thing), and is purely used as a release film or to get the textured surface finish either for aesthetics or for secondary bonding. Because you are using Soric, you dont 'need' a release film except anywhere you are using flow mesh, HOWEVER - I would not recommend ditching the release film entirely. The surface finish you get when in direct contact with the bag is very poor, the wrinkles in the bag leave razor sharp bits of resin that need to be sanded off. You could use a perforated release film (a highly perforated one suited to infusion) instead of the peel ply, which being a plastic are typically easier to remove post-infusion. Personally, I prefer peel ply, but I only use PA66 peel ply which is the aerospace grade stuff with the red stripe. It is significantly easier to remove than cheaper stuff, and it does its job well. Peel ply is also much easier to remove if you cut it into strips (AFTER the infusion, NOT when you are laying it up) and peel it off strip by strip, rather than trying to peel it off as one big sheet. 

2. Yes, you could. However, I would suggest losing the spiral tubing on the vacuum side, you dont  end this. Feed the resin in through a spiral with a port right in the middle to distribute it evenly along the length of the board, and then it will flow fairly evenly across the width of the board, you dont need the spiral on the vacuum side. On the vacuum side I would just have a single port in the middle of the board with a decent size (around 2" should do) brake zone to allow the rest of the board to fully infuse before the resin reaches the vacuum port and starts to be evacuated.

Alternatively, if you do want to use spiral on the vacuum side, I would recommend using MTI hose here instead so that you dont waste resin.

Thank you, that’s just what I was looking for.

I’m not too worried about the surface because I still do a thin sanding coat to finish the boards.

As far as the resin break, I need that piece of pee ply to touch the board correct? I feel like one of the tests I did, I pulled vacuum without anything connecting the vacuum line to the part and the bag sealed on itself and didn’t pull anything through.

Yes, you need a continuous air path between the vacuum 'manifold' and the laminate. Can be peel ply, can be breather, can be fibreglass, can be flow mesh, can be anything that facilitates air flow, but you do need it.

Surface finish wise, I presumed you were doing some sort of refinishing on the board post-infusion, however in my opinion it is much easier and quicker to refinish a peel ply or release film surface than a vac bag surface. It just leaves the surfaces very rough, and then you run the risk of sanding into the fibres before you have removed the resin ridge you are trying to smooth out. With peel ply or release film you still need to do a little bit of sanding, but it is generally quite flat to begin with and it is more just a quick scuff and clean up rather than any heavy refinishing.

I may go the release film route. I just feel like the peel ply wasted a lot of epoxy. Not extra on the part, but just in the excess that was pulled through the peel ply.

Peel ply resin usage in infusion is very negligible, only ~55 grams per square metre. 

That’s not too bad, less than I thought.