Off the Reservation

[Blue_Heron]

The stringers in this boat will have a non-structural foam core, so the laminate will have to carry the entire load. I know I want 1/8” laminate, but the roll of 1808 I bought didn’t have technical info on the label, so I didn’t know how many layers it would take to make 1/8” thickness. I decided to make two test cards with three layers of 1808. I wet them both out with epoxy, put peel ply on both sides, and rolled out the excess resin. Then I put release film and bleeder cloth on one and vacuum bagged it to consolidate it. I was surprised how much excess resin squeezed out of the bagged card. The cured thickness of the bagged and unbagged cards was .10” and .15” respectively. That translates to a much higher glass to resin ratio and a much better strength to weight ratio in the bagged card.

So I started thinking about how to bag my stringer layup to get that high strength to weight ratio. The problem is that by the time I got all the glass wet out and rolled in place, it would already be starting to gel, and vac bagging would have limited benefit. The only way I thought I could pull it off would be to bag it first, and then wet it out. In other words, resin infusion.

Having never done resin infusion before, I decided to experiment with the chine reinforcement I was planning to do. There are lots of Youtube videos on the subject, so I had a general idea about the process. Here’s what I did:

I placed three layers of 1808 in 6”, 9”, and 12” widths.



I covered the glass with peel ply.



Added spiral cut polyethylene tubing for vac manifold and resin lines.



Added tacky tape.



Bagged it and hooked up the vacuum pump.



And then fed it some resin.



And the laminate fully wet out.



Now, I should say that my first attempt was about as close as you can get to a pure fiasco without actually screwing up the end result. I spent about an hour chasing leaks in the vacuum bag before I could feed the resin to it. I wasted about two quarts of resin because I overestimated how fast it would infuse, and it kicked in the bucket. For a while there, I thought it would kick off before it infused all of the glass. In the end, it turned out okay.



That was yesterday. Today, I did the same thing on the other side, but it went much more smoothly.







Yesterday, after finishing the infusion, I got started on cutting out the stringer cores:



That brings the progress report up to date. I’ll be doing family Christmas stuff next weekend, so it may be a while before I can post more progress pics.

Dave