One of the cool things about vacuum bagging balsa onto the lightweight EPS is being able to bend all kinds of complex curves into the foam. We used the soft stuff from Lowes and were able to replicate all kinds of curves into the bottom. Some of the channels were an inch deep and they came out perfect. My brother also made a contour mat and we could make nice single to double concaves without having to shape them.
Once we had the bottoms and rockers pressed into the foam, we’d lock in the rocker with perimeter rails using wood. Then we didn’t have to use the rocker bed anymore.
Very cool. How thick is the cedar?
That’s really striking. So many of the veneers I’ve seen have had ragged and asymmetrical curves.
I think the key to a nice looking veneer is to really focus on getting the shape right relative to the template of the blank. That requires a surprising amount of thought and effort.
Cheers for the replies guys. Anyone got an experience or even a gut feeling with the 6oz/2mm cork/ 6oz deck? I am a heavy guy so I’m going to go 6oz both sides regardless of the sandwich core.
My other choice is mahogany/ sapele which i have some left over stock and i could get a 1/16 deck skin out of. If the cork layup was going to be strong enough as a deck i would rather use that i think as the ply bottom and wood rails are stiff and the board is getting heavier by the layer hahaha.
Veneer at 1/16 is pretty thick. The veneer I’ve used successfully and that GL used was 1/40. Plenty strong. And you can cut it with scissors. And BTW who decided you had to spell scissors with a “C”? Pisses off my autocorrect speller.
Been a while since I did one but you can use a long straight edge and cut up all kinds of cool patterns with contrasting wood colors. If I can find a pic I’ll add it at the bottom. Use 233 tape to hold it together while you bag it.
Thanks greg, I’ll machine it down myself so can go thinner. Was that over 1lb foam? how much was under and over the 1/40
Yes, over 1 LB foam. When I did the multi piece patterns, I used 3 oz under thinking that I needed to hold it all together, with 4 oz on top and a patch under foot. When I did full veneers (not cut up into pieces) I used non woven stuff. The blue strips were stained with water based color. Remember to use a small wall paper roller to press the edges of the veneer into the foam so you don’t have a 1/40 inch step between the foam and the veneer edge. Needs to be done while bagging, in the “cheese” stage of curing. Have fun and keep the pictures coming.
All the best
Thanks that’s good info. I’ll go down to 1/32ish then with 6oz under and over. I am using a perimeter stringer and adding wood rails after the deck skin I bagged so no worries about the Step.
We did the super thin veneers you can buy online from Joe Veneer, I think they are 10 mil thick over soft foam. Wasn’t strong enough for us. The boards with the dark wood here have the thin veneers. The smaller board has a single sheet of Cherry, the other one has Obeche and Sapele. All the veneers were from Joe Veneer. We layered 4 oz glass under and over that. 1/16" balsa was noticeably stronger.
This was with Lowes EPS insulfoam, which I think is less than 1 lb. The Home Depot foam was harder and I think that is 1 lb. I have 1 lb and 1.6 lb stringered surf blanks from the local EPS manufacturer. They supply HD with their EPS. The 1 lb works great with 1/16 Balsa on the deck. Otherwise I do heavy glassing on the deck, like 12 or 16 ounces. Even then the area along the stringer where I sit and have my back foot is showing how badly the foam is being compressed.
Greg Loehr posted a glassing schedule list awhile back. It used to be on Segway Composite website. I believe he said that one layer of typical bamboo veneer was roughly equivalent to a 6 OZ layer of fiberglass fabric. On my cedar stripped deck I think the wood was pretty thick… my thickness planer will only take it down so far. My guess is around 1/8"(?) The list below says that these are minimum recommended layers. I’ve found that for durability, it’s better to use more - same with his recommended resin amounts when glassing. Tests have proven that 3 layers of 4oz fabric with alternating weave orientation are better than a standard double 6oz layup…
Glassing Schedules:
2.5lb EPS - Use one layer 6 or 2 layers of 4 bottom… Use 2 layers 6 or 3 layer 4
deck.
2lb EPS - Use one layer 6 or 2 layers of 4 bottom… Use 2 layers 6 or 3 layer 4 deck.
1.5lb EPS - Use one 4 and one 6 oz for bottoms… Use two 4 and a 6 for the deck.
These are minimums. For strength, go up from there.
GL also said one layer of 1/40 was approx worth one layer of 6oz.
All the best
If you want to reduce dents you have to use denser (stiffer) foam and/or stiffer skin. Each time you double skin thickness you x8 stiffness. If you use stiffer material you increase stiffness too. From my experience 1.5mm (1/16) balsa with 4oz under and over is really dent resistant on 1.5lb eps foam, 1/40 veneer with 4 oz under and over feel and is far less stiff on same foam, dents but feel better for me. Now i use 1mm obeche with 4oz under and 4 or 6 over on 2lb foam for guys that don’t want dents (kite or heavy guys). 2mm cork will dent more than 1mm wood but with a nice “soft” “dampened” feel under foot. Still look ugly for me LOL.
If you can roll up your wood it is veneer. If you can’t it is considered a plank. When vac bagging veneer( the wood you can roll up) you need to poke small pukas(holes) in the veneer to maximize full compression to the foam. Otherwise air pockets can exist and make for inferior build. Personal experience I believe veneer is for aesthetics and planks are for serious strength and rocker manipulation. 2.5 mm thick balsa is equivalent to 10oz of glass with 4 oz beneath and 6 oz above plank.(20 oz glass total and way lighter). Indestructible with a totally sealed and properly glassed board. I personally vac bag foam/4oz glass/2.5mm balsa and then resand, place fin boxes and patch, with a final traditional glass job with 6 oz cloth. Green room resin for best and strongest finish. Just my opinion making my first compsand in 1985 with EPS foam. No digital pictures from build but my wife ,the court room artist, may have something to judge. Attached oldest pic I can find from a decade ago
Guys this is gold thanks. I have trawled the search function and seen and read multiple posts from especially Greg, shark, oneula, Charlie, gdaddy, lemat, john and lots of others and pieced together my ideas from all of those threads but often it’s over 1.5lb or using balsa and other subtle differences. So useful to have you all responding directly and its much appreciated. My friend and I refer to losing hours down the rabbit hole when reading old threads.
I think I will go with 1.5mm mahogany/ sapele and do a seperate cork experiment on the next one. Perhaps will lay the timber across or at 45deg on the deck to improve the flexibility marginally?.
Well deck is on and spruce rails added too. The deck had 6oz under and is made of planks of just over 1/16’’ of mahogany and beech. It is absolutely rock solid and now my main concern is weight. I will sand the deck heavily to reduce some of the weight i think and am wondering how little glass i can put on the outside. The exterior glass is largely for waterproofing as the board is very strong currently. Can i glass with 2oz cloth and epoxy but still achieve a good waterproof result?
Pics to follow including my friends board which we tried to vac the skin on with Foaming polyurethane glue for an experiment. Unfortunately we cranked the pressure up to try and get the nose tight and the result is a good demonstration of what vac bag can do to 1lb foam.
