found trouble need help

Chris S.

Chris S.

Well-known member
I was cleaning the old poly resin from between the cedar planks on my BBSB to prep for filling and fairing with thickened epoxy and I looked inside and found that a rib is cracked. It is cracked along the gap where 2 planks meet. How do I fix this? Do I put a piece of wood on both sides and glue and screw on both sides of the crack. Or should I put a piece of wood on top. What is the strongest fix for this. Here are a few pics they are not the best quilty pics but you can see the problem.
View attachment 20110604135643.jpg

View attachment 20110604140842.jpg
 
Chris,

A splice on both sides of the original rib will give you the greatest strength. The next rib up also appears to be cracked.

I would closely inspect them all.

View attachment frame ribs.jpg

View attachment repair.jpg A piece of 3/8 marine ply on both sides will be as strong as the original rib. The outer edge should be cut to fit. The inner edge of the splice can either be cut to fit or run straight across if you can sacrifice the room. Clean up the original surface as well as you can, then glue and clamp in place.
 
Last edited:
Thanks dave the next rib isn't cracked that's the way it is. I don't know what its called but they fit together half is cut out one each one then fit together and a screw is through it. Its kinda like the way hard wood floor locks together. I will put a splice on the one you pointed out as well. It can't hurt I will check all of them too. Thanks again
 
Last edited:
What would another option be to use rather then marine ply? I don't have marine ply. And don't want to buy a sheet for the small pieces I need. Would outdoor ply be ok? What else would be good to use
 
Chris, you are going to epoxy and glass this right? I would use some composite decking (won't split or crack). Rip a length and glue and screw it to the planking on both sides of the rib from underneath. There isn't much rib there to sister to, and sharing the load to 2 or 4 planks on ether side will distibute the forces. Cut drill and screw everything together so you know it fits right. Then disassemble and paint it with un-thickened epoxy. While the epoxy soaks in, mix a batch thickened. Glue it and screw it!

Dave
 
Last edited:
Use wood to sister on both sides. Epoxy all three pieces, heat lightly with heat gun [will thin and soak in] apply another thick coat of epoxy and screw together. Dry fit and drill and fit all screws first. Stronger than original.
 
Chris,

You may be able to buy a half sheet or partial sheet especially if they have a damaged sheet. Okume or Merrenti (sp?) has more and thinner plys than "regular" plywood and is therefore stronger. Marine fir is a better choice than regular exterior grade ply.

Otherwise White Oak is a good choice. Typically when using solid woods the ribs are cut out of stock that is the finish thickness and steam bent to shape. When they are cut to shape from oversize stock(rather than steam bent) they are not as strong in the areas where the grain runs out or across the width rather than lengthwise.

View attachment ribs.jpg
 
Why not use a piece of steel or aluminum and bolt through? Use some good adhesive with it as well. This is more of a question verses a suggestion.

Mark W
 
Baltic birch plywood would be a possibily and that can be found in small sheets from various outlets. A good cabinet shop might have some they would part with. Good quality baltic birch uses exterior glue and has no voids. Makes great skate boards also..HAHA!!
 
Couldn't you just use some thickened epoxy like when you fillet the side of a stitch and glue boat?
Then cover with cloth and epoxy and have a strong joint?
 
Craig,
I was thinking the same thing. I am going to do some kind of sistering to the rib. I will use some ply and epoxy then use thickened epoxy all screwed together. I think that shound do the trick.
 
Get a piece of1/2 in clear pine(no knots) from home depot it's like 5 bucks. Make a pattern out of masking tape about 12 in long transfer it to the wood, make two pieces for the repair. Pre drill everything first. Place one rib repair on each side Glued it up with PL glue or gorilla glue, screw it together with stainless screws from both sides and call it a day. Be sure to clamp them until the glue dries as it will expand and could pull the repair apart. Let it dry over night. Clean the excess glue off once dried and put a couple of coats of paint on it. It will outlast your ownership of the boat. You can use white cedar, white oak, I'd even venture to use pressure treated ply. It's not gonna be touching aluminum so there shouldn't be any corrosion issues. Chris
 
Last edited:
I think if this was my boat, & if the rib is tight against the planking, I would skip the sistering& make an epoxy rivet. Drill a hole thru the crack on out thru the planking, leaving 1/8 to 3/16" of wood both sides of the hole in the rib. I'd seal the rib& area of planking around it with tape. Prop the boat so the hole is verticle& use a light bulb or hair dryer or somthing to get the wood good& warm. Pour unthickened epoxy in the hole, adding more as it soaks in, while keeping the epoxy warm with your heat source till it just started to kick off. Warm wood, warm epoxy, it'll soak in to the wood& flow thru the crack, bonding the rib& planking all togehter with somthing thats stronger than the wood is to begain with! Just my opinion. Good luck to ya however you do it.
Dennis
 
I say 1/2'' Baltic Birch plywood. It has lots of thin plys. Witch equals lot of strength. Also easy to work with. Go to your local cabinet shop, they will have sidefall from building drawers that should just be about perfect size for what you need.
 
Hey brad thanks for thinking of me. I think imma try to sister the whole rib and maybe a few others as well thanks tho
 
You must log in or register to reply here.
Back
Top