For those who have done balsa construction before, or those who haven’t but know the answer…
For a balsa board that will go on someone’s wall, not in the water (I know, I know… you surf purists are crying out in anguish), what is the best way to get invisible laps?
Is it best to free lap? I would prefer no lap lines.
Thanks for any insight.
Doug
don’t glass it…just put on 6+ coats of varnish
I agree. Varnish is a nice look.
A lot of my balsa boards get glassed with 4oz cloth and polyester, with that combination the freelaps are invisible. I always do a lam resin sealer coat first, however, and that cuts down greatly on any bubbles. If strength is not an issue, and that seems to be the case, you can always use 2oz cloth, which freelaps perfectly and really easily.
While I’ve had some pretty clean cutlaps, they always (at least with my glassing technique) show against the wood. Maybe slightly, but they’re there.
As an aside, I have a similar issue right now. A customer who wants a balsa board and who is clear that the board is to be used only for deco. We decided that it’ll still get a functional glass job (as perfect as we can get it) and I’ll chamber it, so that someone else, at some point in time, might make another choice.
Mahalo.
For a wall hanger, I agree, just resin it, no cloth.
What I often do is cut-lap, but do it along the seam of the rail pieces, if you have them, like you do with compsand. Hides it perfectly.
If you do hand layup, and don’t go too dry, you should be able to free lap however you like, I find the wood is more visually forgiving that bright white foam.
The weave can show over the darker woods if you starting doing too dry lams
Howzit jeffrey, I agree that you should sweet coat the balsa before glassing which besides cutting down on the bubbles it also keeps any oils in the wood from getting to the surface which causes cloudyness in the lam. But I always do free laps.Aloha,Kokua
Thanks for all the helpful replies. I’ve been away from internet access for a few days and couldn’t get back to you.
Varnish sounds good, but I think I’ll go for a cheater coat, 4oz. cloth and free laps, just for a little ding resistance… Dings from moving it around the house, not from surfing.
This board is now at that stage where I can see the light at the end of the tunnel and the adrenaline is starting to kick in. Can’t wait to see the wood all wetted out. I’ll post some pictures when I get it done. Thanks again guys.
Doug
Varnish sounds good, but I think I’ll go for a cheater coat, 4oz. cloth and free laps, just for a little ding resistance… Dings from moving it around the house, not from surfing.
Are you going to use Poly or Epoxy? Epoxy will bond to the wood better, but it costs a lot more money.
It doesn’t sound like you will be moving it around very often. Just varnish it and be careful. Small dings can be steamed out with an iron and a wet towel. The nice thing about varnish is that it is timeless. Over the years your glassed board will start to get cloudy and yellow. On the other hand, you can easily remove varnish, reapply it, and boom it’s a shiny new looking board again.
I have been surfing my varnished board a lot lately, and am very happy with the way the finish is holding up. I don’t have any dings so far – knock on wood 
One more thing, and I’ll get off of my varnish soap box.
These days boards that look woody are becoming more common. In fact, I would argue that having a board with a wood deck is no longer old school. The CompSand people are turning out some beautiful looking boards. It is actually cutting edge to have a wood inlay on your deck. The one thing that will always separate the composite boards from the all wood creations, though, is varnish. If you go to a surfing museum, and look at boards from the 20’s, 30’s, & 40’s you won’t see any glass jobs. If you want an old school look, then varnish is it.
Swied, OK, I’ll bite. Do you use 2 part boat varnish, or some sort of regular spar varnish? Now you’ve got me thinking…
Doug
I used a Pettitt Z*Spar 1015 Captain’s Varnish, and Pettitt sanding sealer.
I posted the step-by-step process that I went through at the bottom of page 6 of the following thread: Balsa Fish Project
There isn’t a lot of info on varnishing in the archives on Swaylocks. I did most of my research by browsing through a wooden boat builders forum: Wooden Boat Forum
After finishing only one board, I definitely don’t consider myself a guru. In fact, I feel a little nervous saying what I have in the precence of all the true balsa guru’s on this site.
Doug,
I think it depends on what look you are trying to acheive. I’ve done my share of re-varnishing boat bright work, and getting that high build, deep luster from varnish takes quite a few coats, so your up against at least a weeks worth of painting,drying sanding, painting, drying, sanding, painting, drying, sanding, painting, drying then finally rubbing out. Also don’t you want that high build fillet around the fin & board deck. I’ve never seen a crystal clear glass on fin done with epoxy? And I’d don’t know how you would attach a fin with varnish?..So I’m thinking old school Poly.
Also varnish is not 100% completely air tight. Over time the board is going to expand and contract through the seasons. This will show up in cracking and checking of the finish, especially the glue lines around the different densitiys of balsa sticks…so, just like a boat, eventually your going to have to either recoat, or completely re-finish.
Fiberglass and resin will encapsulate the wood for eternity, keep the wood from moving, and seal it as close to water tight as it can get.
My gut tells me, to tell you to make it like a surfboard. That means fiberglass and resin. I’d do a cheater coat with lamresin to seal, I’d do a 4,4 top and a 4 bottom. Your not going to get any bubbles with a 4 oz job, your skills are well beyond that! then I’d put a thick hot coat, sand it baby butt flat, and maybe do it again for ultimate flatness, then I’d put a thick gloss and polish it out to 2500 grit, then I’d use some 3M Mirror glaze polish… That would give you about 1/8-7/32 in of protection, and a shine only a wall hanger should get.
Use the glass, make it a surfboard
Resinhead, After mulling it over for a while I came to the same conclusions as you. The stickler was the fin: I made a custom glass-on fin to put on this particular board, and if I varnished it, there would be a this nasty fin attachment problem.
Since I have plenty of 4 oz. cloth at the moment, and it seems that 4 oz. is the best for clean free laps, I’ll be gearing up for that.
I have dealt with Z-spar a little when I worked in a custom woodworking shop. It’s great for exterior wood projects. We used them on carved doors. But it looks like polyester resin for the balsa board.
By the way Swied: Your varnished board looks great. It appears that you mortised the fin into the board…good work.
Thanks to all for your input and suggestions.
Doug
I was going to post the samething. I wasn’t trying to jab at the varnish coating thing, and Swied wood working skill are fantastic. it’s just that if you tring for a certain look, only certain materials can give you that look.