Making pre-made comp/sand skins from thin veneers (pic heavy)

General Discussion
1

okay comsando commandos…

I need some advice…

Over the past year I bought a bunch of veneer lots (shown below) that I want to somehow epoxy up into premade skins for future compsand projects.

Unfortunately the stuff is only 1/42" thick and I’d like to bag it with glass into 2’x8’ patterned sheets with a design.

I need to find a way to gain thickness with some type of filler but still keep it flexible enough to wrap around the board.

Be nice to get it to at least 1/16" which is the thickness of the thinest balsa we use…

Any ideas or techniques?

One of theses day’s I’ll figure out how to get into the pre-packaged skin trade. I know you can get large sheets of a single veneer but nothing with patterns of a combination of woods…

Here are some of the veneer lots I’ve picked up over time from JoeW, you can just imagine them as a skin core.

Rio Plansidor and Etimoe

Figured Maple and Koa

Tigerwood and Ebony

Sycamore and Sapele (figure Mahogany)

Purpleheart

The next step wil be to figure out how to do something like this without going broke on my board.

2

Purdy wood,

Maybe lay up the skins with some 3M super77 on thick paper then bag at 24hg with plywood-mylar-glass-paper-wood-glass.

Paper backed veneers are the norm and they work fine with resin.Or use some thing that adds more strength like silk,bamboo,glass,pvc foam, rice paper,ect…If you only put glass on the under side of the skin it would add a lot of flex for the top skin.I am liking the premade skins idea even if I only use it for the bottom skin.

Let us know how it goes.

Ian

3

Nice looking wood!

Here’s what I would do to make premade sheets…

Get some bundles of sheets of the some 1/16 balsa from lonestar, and lay it all out so the seams don’t fall on the same places as the veneers seams, then bag them together with no glass (just a layer of epoxy between) on a sheet of flat formica.

The problem I found with big flat sheets is that they require relief cuts on the compound curves, like where the wood curves up the nose and over the rails at the same time. See the crooked lines running perpendicular to the stringers in this pic…

That problem would be compounded by using great big sheets.

If the goal is simply to get a great looking veneer board, with great strength, there are two ways I’d approach it knowing what I know now.

  1. Make a standard compsand board with 1lb eps, 1/2 rails, and 1/16 skins. Then put your veneer on in a separate process. The rails are super-fiddly, and the only one that I did that I was really really happy with was the makore fish. Took many strips to make the turn around the rails, and much blending and feathering and patching and feathering.

  2. Shape your board out of 2lb foam, bag your veneers directly to the board with an extra deckpatch of glass under. Don’t worry about wrapping the rails, just cut off a half-inch and add on balsa rails then shape them down. That would give it the Jensen look. This method is surprisingly durable, you wouldn’t believe how well my fish is still holding up. Not as much as compsand though.

  3. Same as above but with 1lb eps, and 1/16 balsa deck/bottom skin before the veneer and rail cutoff. Heaviest, but toughest. Would lose the benefit of having the deck skin overlapping the rails though. flexible, but with a “squish point” right at the joint.

  4. Just shape it from 2lb eps (with stringer) and do it like I did it.

If you’re looking to put lots of cool designs in it, I would just tape it all together on a flat surface with some really cheap masking tape, and plan on that tape staying under the veneer when you epoxy and bag it to the blank. The more joints you have in the design, the better it will conform to the compound curves of the board. By just having it all masking taped together, you give it some room to move around to make the curves. If you have it already pressed into a premade skin, it’ll be tougher to make those curves.

That all being said, I have heard some scuttlebutt about some folks premaking their skins, all flat, but I’ll be damned if I can figure out how they make compound curves with them.

Good luck and keep me updated!

4

I know someone who use’s the same thickness veneer 1/42” (0.6mm) and just vac bags it with 4oz under and over onto shock horror XPS (with centre stringer). Rails are not wrapped in veneer but done with tints or fabric, Boards look very good and by all accounts some have stood up to 5 years abuse down at Marget river… Use WRC or hoop pine venners as these are lighter density wood ~ 350-400 kg/m3

To keep the weight down you would not want to laminate up sheets of it into thicker skins as I would guess most of the densities of the hardwoods are around the 700kg/m3 (~44lbs/ft3). However you could vac bag it onto 2-3mm thick PVC and then use it as a sandwich skin.

cheers

5

thanks j

the hard part is you want to create a pliable skin somehow using something to sandwich the veneer in between so you don’t have to sand it because sanding 1/42" only leads to sand thrus and patching. I bet you know what that’s like…

there’s some stuff from ACP I have that TJ turned me onto but I don’t know if it makes sense to put it on the underside or over the top to build some depth to protect the veneer.

I’ve tried some of those methods…

First attempt was using 3m spray 70 glue to adhere walnut veneer to 1/16"x4"x48" balsa strips and then build out the skin as normal. But somehow the balsa sucked the glue dry and the walnut peeled off before I could finish sanding it.

second attend was a fish i did on 1/6" balsa first and then veneered with mahogany and birch over than. Still ended up with a sanding problem and delams.

I definitely learned not to wrap this stuff and just do solid balsa rails.

But after seeing what DanB and JJP have accomplished with their pre-glassed balsa skins makes me think it can somehow be done with this. In fact I know it can because Gary Young was doing it 20 years ago with his boards.

I might try to skin the shaped blank with the woven bamboo laminate and then GG the veneer over that(Ithink this is a G Young technique) to fill the gaps but then you still have the ultra thin exposed wood to worry about unless you somehow glue on the veneer while doing the outside glass in a bag at the same time. Which is how I believe Surftech does it.

I’m also debating about glassing the the first with 2oz to create a hard shell and then vacuuming the skin on over than with gorilla glue. I hear that’s how Kevin Ancell and Yater put the shell on the boards, they glass they first and layer the paper thin shell over the top of that… A epoxy fiberglassed strengthened board with a virgin wood shell that you can hand rub and smell is what I’d like to achieve one day…I’d really like to be a bug on the wall and sit in on Chris Garrett’s shop to watch how he makes his wooden cedar boards that don’t require glassing…

Does that Makore fish still sing to you?

I thought only the hollow guys like Paul experienced that feeling…

6
Quote:

But after seeing what DanB and JJP have accomplished with their pre-glassed balsa skins makes me think it can somehow be done with this.

The key to preshaped skins is all in the angle of your rail cuts and the orientation of the wood. I would either go with Shwuz’s approach of gluing it to backing material maybe taping it together with that tape from Joe Woodworkers and some veneer softer. I know you don’t like the perimeter rails, but it would really make your job a lot easier. Pick a nice looking wood like red cedar and you’d be very happy. Instead of overlapping the rails like Bert does go with them as a cap (they wouldn’t be as structural, but they would really pretty things up). You could get by with 1-2 thin strips.

7

Hi Oneula,

Is this the stuff from ACP?

Aeromat

A honeycomb foam mat, used to add thickness to composite laminates. Unlike Nomex honeycomb, AERO-MAT is very flexible and will conform to compound shapes. Ideally suited for reinforcing epoxy fuselages where additional stiffness is needed.

Seems like it would work.

-Rio

8

I have a sample of aeromat. It sucks resin. Lots of pore space.

Oneula, I’d just do it like Dan said. Make your skins with 4 oz glass & epoxy on both sides, on a flat (wet-out) table, undervac. When you go to make boards, bag the bottom skin first on a blank that’s still a rectangle. After that, you template-cut it, shape the deck side (dome, rail bands, etc.) and bag on the other skin. Then flip it back to the bottom & use a flush-edge cutting router bit to give it a good square edge all around. At that point, it’ll only take one or two pieces of the wood of your choice to make rails thick enough to shape again. With the right amount of clamping (offcuts or bag) and the right thickness of rail strips (1/4" for balsa, 3/16" for pawlonia or redwood, 1/8" for cedar or bass, etc) they’ll go on perfectly and Bob’s your uncle.

Personally - and this is 100% subjective - I don’t like that you can see along the edge of a Surftech that they tried to blend the veneer & make it look soild. Trying (and failing) to hide something is aesthetically worse than just showing your craftsmanship…

In a way, I think Firewire with their exposed wood rails is giving a huge green light for lots of us compsanders to show our work.

9
Quote:

I know you don’t like the perimeter rails, but it would really make your job a lot easier.

No you got it all wrong

my bro and I are 100% Prail after the fact converted

just like how Benny describes below

Quote:

When you go to make boards, bag the bottom skin first on a blank that’s still a rectangle. After that, you template-cut it, shape the deck side (dome, rail bands, etc.) and bag on the other skin. Then flip it back to the bottom & use a flush-edge cutting router bit to give it a good square edge all around. At that point, it’ll only take one or two pieces of the wood of your choice to make rails thick enough to shape again.

The debate is what to make the rails out of.

Bert says balsa

Gary Young says corecell

Someone else says pawlonia, bass or cedar

so far I’ve done them in pure balsa, balsa combined with cork, corecel, and blue dow but resawn cedar and or redwood is next… so it’s not that part I have a problem with

but more how to make a skin I can roll up and stash on the side till needed

or store between some sheets of ply on a rack till needed

just like your glass roll or your stacked blanks or resin containers

skins should be the same way.

It seems the answer may be to build a DanB skin with just one more layer

so instead of glass>resin>balsa>resin>glass in bag on a table covered with mylar or perf release and a blotter,

it’ll be glass>resin>1/32" balsa>glue/contact cement>1/42" veneer>resin>glass in a bag covered by the same stuff.

Then you’d still have a sandwich to apply over foam albeit the skin characteristics may have been altered by the characteristics of the additional wood layer and it’s grain pattern could be good could be bad. which leads to another diversive thought…

But if you built it just right…

I mean a complete compsand glassed and all…

couldn’t you just bag the veneer over the finished board with some PU glue or waterproof contact cement

and create a glass-less wood exterior (like Chris Garrett’s woodies) you could seal and buff out like another other fine piece of wood furniture? You’d just have to plan out the rail seem a tiny bit so the rail seem would blend in with the 1/42" overlay.

Kind like how Ancell glues on those shell lams on to a finished yater. kind of like a fake olo or alaia

Aromatic Cedar or Camphor would make a nice exterior shell and keep the bugs out of the EPS storage area.

I’m getting psyched…

Cause I realized I already did this on my Jim Turnbull 10 footer with Madrone…

but stupidly I glassed the outside to seal it and gave it Mcdonalds supersize-me weight…

10
Quote:

The debate is what to make the rails out of.

There’s no debate for me - the balsa, pawlonia and bass are too light colored to work with those nice, bold veneers. There’s a lot of love for the GG type glues to attach the skins, etc… but not from me. I don’t feel that they have any place on a board. I haven’t used it for at least 3 boards. I’m not sure prefabing a bunch of skins is the way to go - it has to do with resin cure and memory. I would make 1 and let it sit for a while to see how it holds up. Its better to be safe than sorry.

11

Hi Oneula,

You could just bag the veneers with some glass on one side. That would give you prefab panels that you could use in the future. Then if you decide that you need glass on the outside you could still use it. I guess what I’m saying is that those veneers are really beautiful to commit to a certain glassing schedule for a panel. If you only glass one side you would be able to adjust the glassing schedules that you want (or no glass) but still be able to have handy panels that you could easily work with.

DanB has also a point that the memory and curing effects might affect the skins.

Cheers,

Rio

12

Hi Oneula -

The memory and curing aspect is what has me spooked.

I know Paul Jensen tries to clamp his skins to the frames the morning after laying them up - while the epoxy is still flexible enough to bend to shape. Probably the same holds true with vacuuming?

The bottom skins might handle simple curves under vacuum but it seems to me the curves of the deck would be a problem once the epoxy fully cures. Maybe if you molded the deck skins over a finished board - sort of like how you’ve been doing your rocker glue ups? You’d have a rigid shell of the deck.

Your final shape would have to be pretty close to the deck you used in the molding process. Even then, unless you’re computer machining to extremely close tolerances, you’d probably need GG or foaming epoxy to fill the gaps.

Once you had the deck shells fabbed, you wouldn’t be able to roll them up and store.

I suspect that if you had a big enough freezer you could store rolled up pre-fabbed skins in a state of semi-cure until you’re ready to use them. I think Roy Stewart (?) stores his used epoxy brushes that way and they keep for a long time… until they reach normal curing temperature anyway.

Some pre-preg carbon fiber cloth is stored that way. Some types have to be heated quite hot for full cure. Until then, they are basically frozen liquid epoxy saturated cloth.

As for the “squish zone” where the skin meets the rails… One of those methods listed in the “A”, “B” or “C” thread showed an internal perimeter stringer with the skins overlapping followed by rail build up outside that. The internal perimeter piece would help support the skin and prevent squishing at the seam. Seems better than trying to blindly “feather” the skin and finding out (or not finding out) how thin it is by sanding all the way through.

If the strength is dependent on the skin core, seems you’d want to save as much of the thickness as possible - especially where it meets the rail at the squish zone.

The built up perimeter rail with internal piece supporting the skins makes sense on several levels…

13

The debate is what to make the rails out of.

Bert says balsa

Gary Young says corecell

Someone else says pawlonia, bass or cedar

It all works…just pros and cons with each.

Different mat’ls can be blended for the desired affect.

Dont like Balsa’s water absorbing characteristics there? Use Corecell.

Like the flex and pop of wood there? Use Cedar.

Want both? Combine them.

I dont like Balsa all that much…esp in the rails…went surfing the other day and dinged the rail a tiny bit…just kept surfing, no worries. And, its still unfixed…ok to surf. Peace of mind is a wonderfull thing…Ignorance is not bliss in this dept.

14

If I was going to store skins flat, I’d definitely only glass one side. Even fully cured, wood with glass on one side will still be very flexible. But make it a sandwich & you lock it down. I suspect the same would be true if you glued balsa to veneer - then you’re just making homemade plywood.

The one-side-glass skins would also be most flexible if the glass was on the inside, so as you bagged the skin on a blank the wood side was the one that stretched. A single piece of cured epoxy-glass may be pretty flexible, but its not exactly elastic. Let it take the short route around the curves.

Don’t be afraid of foaming PU glue. I’ve got a board (10’1" Noserider) that got pre-made skins (glassed inside only) attached with Elmer’s Ultimate and then hand glassed on the outside. I’ve surfed the crap out of it for the last 6 months or more. I took it by Icons and Dave tried to buy it. I’ve surfed it in everything from ankle-slappers to a couple feet overhead. I’ve stood on the bottom & bounced. And after all that, I still had no concern about sending it to Baja with a friend a week ago. He’ll be gone a month and that board will be subjected to as much sun, rocks, and big surf as it can be - and I have a feeling its going to come back to CA in much better shape than his Pearson will. Whether he ever gives it back to me is a different story. :slight_smile:

Its got rails just like John showed above. The first layer, though, under both skins is endgrain balsa scrim on a fiberglass screen. It’s totally non-structural in a stringer-type way, but it provides great support for the edges of the skins & a nice gluing surface for the visible balsa rail pieces. Its also easy to apply - you just wet the square edge of your blank with epoxy & lay it on, cloth side to the epoxy. It drapes around the curves & completely stays put, no clamping, no taping. Easy peasy.

15

not sure if any of you guys have bought alot of this stuff but it comes in little boxes or tubes even the 4x8 10mil paper or wood on wood back 20mil veneer come in a 4’ long by 10" box. So rolling it up after glassing the 1/42" with 2oz or 4oz E should be no different. Perhaps glassing the outside and then using this stuff on the wood side using the vacuum bag to “mold” the glass backed veneer to the compound curve before securing it with glass epoxy of just glue…

You can achieve some significant shaping using this stuff…

http://www.joewoodworker.com/…g/video/softener.wmv

this way when I secure the “molded” form tot he board I can bag on the external glass with mylar perf release to get a showroom finish on the outside prior to finishing up the rails like John described in his drawing. Deck overlap yes bottom no…

This is what I want to end up with…

versus dealing with the experience of bubbled or delamed veneer…

16

as far as keeping the laminated veneers somewhat flexible, there are some two stage resins

that can be “A” staged and remain fairly pliable, then bagged onto your mold(board) with heat to complete the cure.

Most of the two stage resins require refrigeration, but the was an article in Proboatbuilder a while back on room temperature pre-pregs. You would basically be creating a woodskin prepreg ready to go in the bag over your shaped blank.

Just some thoughts/reservations:

I'm not sure how flexible this would be at "A" stage.

How hot would the skin have to get to complete the cure "B" stage.

Hope I didn’t muddy the water.

Pete

17
Quote:

Get some bundles of sheets of the some 1/16 balsa from lonestar, and lay it all out so the seams don’t fall on the same places as the veneers seams, then bag them together with no glass (just a layer of epoxy between) on a sheet of flat formica.

Wouldn’t it be better to use the ultralightweight glass they use for modelmaking (less than 1 oz pr. square foot) for the glueup? I would think you would actually use less resin that way compared to rolling or painting it on and hopefully the resin will hold on to the epoxy somewhat and give you a nice even spread.

regards,

Håvard

18

Yikes on those boards. My experience with the skins is that they are plenty flexible to conform to the deck even with both sides pre-glassed. I liken the stiffness of the skin to that of the cardboard in a twelvepak. Yes, I’ve thought of making a Budweiser panel for kicks. I suggest making the skins using both balsa and veneer in one piece. One thing I notice when applying the deck skin is it’s important to get it cut to size first. Too much overlap at the rail and it wants to stick up high and proud off the rail, the gives the bag some leverage to try to lift the skin off just inside from the rail. Be careful with how small of a radius you are trying to wrap the skin, there is a materials limit. I also agree with the use of epoxy over glue, epoxy is just a better bond period.