bedding the stringers

[Kracker Jack]

thankyou for the compliments on the project thus far. As you can tell Im addicted to this web site and addicted to this build, I feel like with all my posts that people think im trying to take over this site!! lol!! I have looked and researched alot of other "boat building forums" and your right everybody has a different opinion on certain techniques to use when it comes to glass work.I am very opened minded and always appreciate all info and tips you guys give me on my project. I built a motorcycle last winter and have never even built a bike before i did it as a challenge just like this boat.

[cterrebonne]

i dug up this thread from another website. they talk about bedding the stringers

http://forums.bateau2.com/viewtopic.php?f=10&t=25844

[reelapeelin]

Originally Posted by cterrebonne

i dug up this thread from another website. they talk about bedding the stringers

http://forums.bateau2.com/viewtopic.php?f=10&t=25844

I understand leaving flex between stringer and floor deck...but he also says keep stringer OFF hull...WHAT??...

[RidgeRunner]

Full floating stringers is another method of building Reel. Cut some wood spacers, place under your stringers and tab them into place with some cloth wet out about every foot or so. Let it kick, remove the wedges, touch sand and lay the glass to it. Anywhere the plywood stringer comes in contact with the hull is a potential hard spot. I don't like the void it leaves under the stringer but I would consider this route if the boat wasn't getting any foam flotation, just install the limber holes. I would also coat the stringers with resin just in case water finds its way into the void. Filleting is the same procedure and would need to be done after tabbing.
By bedding, you are putting a small flexible barrier under the plywood stringers. You can use small wood spacers here too to ensure no plywood is contacting the hull. I like it because it fills voids where the stringers aren't conforming to the hull 100%, and it holds the stringers firmly in place. The layer(s) of glass you put over the stringers overlaps onto the hull and distributes the load.
If the plywood stringer is flying in close formation with the hull but only touching the hull in one or two spot 2" long, after glassing it in place the plywood can actually be pressured up against the hull bottom due to shrinkage of the resin. Some small boats have obvious hard spots just looking at the wavy gelcoat but are perfectly safe for what they were intended to do. Hard spots tend to spider crack gelcoat before catastrophic failure and stand as the main reason I don't like bottom paint.(hiding agent)

[Curapa]

Like what was said earlier about skinning a cat. You are not going to find that everyone agrees on what methods to use. Do some research and make the decision. I prefer the method of using Epoxy glue on the underside of the stringers so in a sense my stringers would be about 1/8" off of the hull also.

Wood flour from a cabinet shop would be fine as long as it is clean with no debris. Remember polyester resin kicks way faster than epoxy, you must thoroughly mix the resin before adding the filler. By the time the filler is mixed in, it's about at its setting time. It's nice to mix up some epoxy and have all the time you need to spread out one continuous fillet. You just may find that you will spend more on the polyester because of the amount you throw away. I would say at least use epoxy on the stringers, glue and fillets and switch over to polyester for the deck and such. I am not going to get into the epoxy vs. polyester adhesion argument as it has been beaten to death everywhere.

For the deck, I would just use some 20oz. cloth or so, no need for the 1708 there.

[RidgeRunner]

Agree with you Curapa. Not going into debating epoxy vs. PE VE. If PE or VE just know that the surface prep needs to be 100% as they lack the adhesion properties of epoxy. Rough the hull up with some 36 grit to aid in the mechanical bond. I purchased a 5 gallon kit of putty, and have seen others do the same with great success. Mixing the hardener in with the putty in small batches will give you some idea of your work time. Large batches take longer to mix and have a exothermic reaction that tends to harden faster so getting it spread out fast is the ticket. I know all too well about throwing out resin/putty that kicked in the bucket. Frustrating. All you can do is drop the pail and grab another.

[bradford]

Good exchange of info in this thread. I'd be interested to hear what Skools Out thinks about the stringer issue.

Looking good Kracker Jack, keep it up.

[peiserma]

I've been researching info on this very topic, and found a video produced by ShipShape TV. Although this video is about a specific product, the narrator mentions that wooden stringers should not be touching the hull directly (that part is towards the end of the video):

http://www.youtube.com/watch?v=8Muf7G3T7Z8

As RidgeRunner already mentioned, the bedding compound serves the purpose of keeping the stringers off the hull. I like the idea of putting small spacers (kinda like shims) between the stringer and hull before bedding it down. That would prevent you from accidentally pushing the stringer too far into the bedding compound. What kind of thickness would be appropriate? I'd guess 1/16", or would you want as much as 1/8"?

[Curapa]

On a side note: The host from Ship Shape really gets on my nerves for some reason.

[Kracker Jack]

Factory stringers in my 74 are spot glued every foot or so. Read a thread on a forum lastnight that said a guy who has been building boats for 30 years has never heard of the floating or spot glueing stringers I thought that was kinda odd