JEM Watercraft

Thanks for the tip, but since I really don't have an indoor workplace, I'll be building it outside in the back yard. I'll cover the project with a nice tarp for the wet months.

I cut the strips inside and had dust all over me. Put the panels together and then outside to sand them , a lot of dust on me. No matter where you work on the wood you will have dust all over you , just a fact of life. Use some breathing protection.
On the lighter side save the sawdust and sift it so you have the fine wood flour to use for the fillets. Same thing when sanding , have a sander with a dust catcher bag on it and empty it often. I emptied mine into zip locks and had enough wood flour for several boats.
The red wood dust ( wood flour ) when mixed with epoxy for a fillet has a really nice deep purple color to it. It can be mixed with other wood flour , say pine , to make a lighter color or just use some glass bubbles to really lighten it.

Use extream caution when mixing the glass bubbles they tend to float away when ever used , measured or mixed.

I've been checking around, and unfortunately since I only have a hand saw the stripping is definitely not going to happen, I've see Ron use Lauan plywood for his build, was thinking using that with fiberglass cloth instead of tape. I know it's a trade off on weight, but I wonder if I can still get it at under 50 lbs?

which model?

Matt, I'm trying to cut my teeth on the free Laker

You should be able to get under 50 with cloth and the "exterior grade" 5mm ply the big box stores sell.

If I remember right, my Laker came in at 54 pounds using 5.2mm hardwood plywood from Lowes. $12 a sheet 2 years ago (they called it luan). Probably could have been lighter if it had been built by someone with experience laying on glass. It's been a great boat and I get a lot of compliments on it. Been camping twice in it. With me and gear it was carrying something like 275 pounds. I came back across the bay (1 3/4 miles) from my camping trip last month in what seemed like 3 foot waves and 20 mph wind. I was pretty well soaked when I got back, but I did get back. What fun!!



Bruce

I haven't carried the sort of load that Bruce just described but have crossed an open stretch in what sounds like similar conditions. While I wouldn't recommend the Laker for this on a regular basis I did find it was surprisingly capable when the need arose.

My belief is that because a basic boat can be built of marine ply with taped seams only then one done with a lower grade of ply really only needs a light layer of glass to stop checking, possibly plus tape on the outside of the seams. For 5 mm ply or thicker I would be looking for about a 2oz glass, and I reckon you could get close to 40lb if careful with the resin application and fillets.

For the record my Laker is made of 3.6mm exterior grade ply with 2.5oz glass, has far too much resin on the hull and weighs around 35lb - although some of the weight saving is possibly due to all the voids I discovered in the ply after the build . With over 40 hours logged in it so far I can say it is not a flimsy boat.

I hammer a boat pretty hard, so I have some definite ideals about the lay up .
I used 4 mm on my Laker (3/16) 6 ounce glass inside and out and still came in around 35 lbs.
A couple things to think about on cloth weight and what I believe to be the best layup. If you are covering the boat with epoxy inside and out you may not be any lighter than with full glass coverage, 6 ounces to a sq yard isnt much in weight and it takes less epoxy to cover it (the cloth displaces some of the epoxy). Your strength is way higher with cloth inside and out.
The outside cloth is for wear the inside cloth is what will make your hull take a hard blow and not fracture. Think about it when you hit a sharp object the outside glass folds inward not much strength there, the inside glass has to stretch to break and is much stronger .

You are spending the time and money to build a boat ,one or 2 lbs for double the durability and strength,maybe even less weight thats a no brainer for me
Ron.

Thanks for that tx river rat, I have been tossing up whether to glass my Sobalo inside and out or not. I was thinking not to glass it inside to save weight but you have answered that one nicely. Makes sense the way you explain how the glass strengthens from the inside better than from the outside.