Balsa Lay up

[Liqui-Fly]

I've decided I want to lay balsa core over the top of the tunnels...partially for asthetics...partially for droop. What goes over the top for a nice finish and to help with compression? Also do you need to open all of the gaps by placing over a drum or something like that or will the resin penetrate without doing this?

David

[AlaskaStreamin]

David,
I just laid up a lid to cover the splash well in my Bayliner Trophy using Klegcell. (It's in 1" squares like the balsa). After the core is laid into the hull and is bedded in nicely, just roll on some resin then go with a layer of mat and some cloth. After that I use a ribbed roller to work out the air bubbles and it also works the resin into the balsa. Try this on a scrap piece to get your wet out right. If you don't use enough resin, the balsa will soak it in and make the glass on top too dry. On the other hand if it's too resin rich, the glass will be brittle. Do a test then cut the balsa in half and see if the grain has absorbed the resin into the middle. If it does, you won't ever have rot. One trick is to keep the balsa as dry as possible (humidity)so it will "wick" the resin easier. Another trick is to thin out the resin with Styrene (10% max). This will aid in the balsa saturation. You can also wet out the balsa, let it dry then lay the glass on. You have 48 hrs to lay glass over glass before having to rough up the surface. After the cloth is on, you can use a bondo spreader to work out any resin rich spots.
One last trick is to lay wax paper over the final lay-up and work gently with a spreader. It lays down all the edges and smooths out any seams. After it dries, peel off the wax paper and you'll have a smooth non sticky surface. I use this trick when doing wear strips on Boston Whalers.
Good luck!

[Liqui-Fly]

I wasn';t sure if you wanted the actaul core in resin too. Figured it would add too much weight (8 oz's) hehe. I was considering using peel ply and pulling vacuum and then sanding and buffing after adding another wet out coat over the textured peel ply surface. How would 8.5 oz e-glass be over 1.5 oz mat work/look?

David

[AlaskaStreamin]

I've never used E-glass. We have a limited selection at the local glass suply store. Try a sample lay-up and see if you like it.

Snow boards are the big hit this year. I have one board and three kids. I pulled a mold off it and am laying up four more for my kids as well as my girlfriends two. I'm using up all my left over supplies to build these. OOPS!! Is this a "splash?":eek:
Have fun!!

[Liqui-Fly]

Now that whould be cool with some carbon fiber strips or tow for strength and looks:cool: Can you buy thin film sheets for the running surfaces? Is it just PE? What about edges?

David

[Liqui-Fly]

Did a quick search...it's polyurethane.

[Wile E. Coyote]

I used E-Glass over regular matt on a repair I did a couple of years ago. It left a very smooth finish that needed no fillers before gel coat (of course that depends on how smooth the underlayment is...) It looked great when it was done...the only reason I geled over it is it didnt fit with the rest of the boat....
Bill

[Liqui-Fly]

Thanks.

David

[ShipBear]

" You have 48 hrs to lay glass over glass before having to rough up the surface. "


How about the " wax ".. Glass builds up to seal it off from the air to cure..??
With in 48 hours is OK to lay another layer of glass over glass already laid down.. Without doing anything to the first layer..?
I have a lot of Balsa core to lay in my hull.. And was thinking about this.. Thanks for any Info..

Later Larry

[Backfire]

There is no wax in resin unless you buy resin with wax put in it. Some resins are made to stay tacky- to receive another layer. I don't care for them personally. A good GP (general purpose) laminating resin will cure tack free, a low profile, a modified polyester, epoxy, etc...You need to know what you are dealing with and that it fits the project. I would scuff each layer-piece of 60 grit- just to knock of the stiff hairs so the next layer lays flat. As far coreing goes, the ideal sandwitch construction has an equal amount of glass on both sides. Double the thickness, ='s 9 times the stiffness. Not many do it that way. Good luck with the project.
Backfire ;)

[ShipBear]

The wax is what makes the resin set up...
laminating resin doesn't have wax to seal it off from the air so it want set up till covered with something to seal it off from the air..
Not talking about laminating resin .. But the regular resin that gets the buildup that you have to remove befor you lay more over it, as in a repair.. What would be the time limit you have befor you have to clean the wax, blush or what ever off. befor laying down another patch on top..?Someone said you have 48 hours..
But that sounds way to long to me.. BUT I been wrong befor.lol

Thanks for the info, Larry

[Backfire]

Yemme try one more time. There is NO wax in resins unless somebody puts it in. Wax does not "make it set up", catalyist makes it set up, go off, get hard. The function of an added wax is so that it floats to the surface to seal off the surface so that a more complete cure of the surface occurs, handy on gelcoat patches-thats what Patch Aid and similar products have in them so when you shoot the final top coat, you get a complete cure on the surface, so you don't have to use acetone to wash the surface slime off to get to the hard stuff. And why would you use a waxed product on anything but the final surface? Using a waxed product and having to really sand the living **** out of it each layer is stupid. The surface cure of the some resins, say a lo-profile is quick and 24 hours later you better bust the surface glaze by sanding if you want to count on a full bond between layers. Epoxys have more "bite" and tend to etch into each other. You may consider curling up with a good book on basics of fiberglass repair. It's art and science together, get the science part down 'cause the art part will give you enough problems.
Backfire ;)

[Liqui-Fly]

Well I'm using epoxy so don't get all upset guys. I found a clear finish epoxy and am currently working on some UV stabilizers. If they fail I'll top coat it with varnish or urethane.

Blush is with epoxies. It's know as an amine blush. The amine is a functional group involved in the chemistry of epoxies.

Polyester resins are formed from what is know as a condensation reaction. This means the reaction produces H2O as a by product. Allowing for outside moisture messes up the equilibrium of the reaction which can cause some problems with the surface curing. This usually isn't anything more than haze. That's why wax or PVA is used. Because I want the floor to look nice I may have used a resin with wax or sprayed PVA to get the super sweet finish...but I'm going with epoxy and am going to fight the UV battle. Exposure will be low so I think it will be a long lasting beautiful repair. Time will tell.

David