Hi if i wanna repair by laminating ribs?

[niander]

Hi i got this strip planked carvel folkboat so the planks that are about 1 3/4 " wide are all glued together
if i wanna repair by laminating ribs in there do i have to stop the epoxy gluing to the hull with plastic?
and also once the ribs are in place i will have to put in screws from the outside...how far apart would you space the screws ?
the hull is very well glued together still.
cheers

[nessboat]

What exactly is the damage?...If the hull is strip planked then the ribs will probably be glued and screwed to the planking and at the size of planking you state then one screw per plank into the ribs.

[Rich VanValkenburg]

If the new frames are glued to the planks it'll make it more difficult to repair/replace a plank later. You never know when you might have to do that, collision, soft plank, etc. If the originals aren't glued in, and I doubt they are on a Folkboat, I'd follow suit.

some of the pain I went through, I screwed the new frames in place.

http://i115.photobucket.com/albums/n287/falcon5a/rib2.jpg
http://i115.photobucket.com/albums/n287/falcon5a/rib3.jpg
http://i115.photobucket.com/albums/n287/falcon5a/rib4.jpg
http://i115.photobucket.com/albums/n287/falcon5a/rib5.jpg

[JimConlin]

Do I understand correctly that there are now no ribs?

If so, any expansion or contraction in width is now unrestrained.
I'd worry about what would happen if something inelastic, like a rib, is firmly attached to your planking and the planking expands or contracts.

[peter radclyffe]

on a strip planked hull you can glue them in & follow any original fastening pattern

[JimConlin]

on a strip planked hull you can glue them in & follow any original fastening pattern
What if there are now no ribs and therefore no original fastening pattern?

[Cuyahoga Chuck]

I'm confused. A stripped hull is different than a carvel planked hull. And in neither are the planks glued together. If the expansion/contraction cycles are constrained something is going to pop.
In either of these types of construction there has to be ribbing of some kind to hold the whole mess together. I've heard of it being screwed, clinch-nailed or rivited but never glued.
And I always thought that a place like the Outer Hebrides, with seawater on every side, would have a wee boatwright behind every rock.

[peter radclyffe]

im confused too, what we call a strip planked hull is usually glued, if there is no fastening pattern glue the ribs & fasten them, maybe every alternate plank

[ShagRock]

You could use steam bent ribs to follow the curvature of the planks, clamp or tack them at the ends, and use your choice of fasteners.


I'm confused. A stripped hull is different than a carvel planked hull. And in neither are the planks glued together. If the expansion/contraction cycles are constrained something is going to pop.
In either of these types of construction there has to be ribbing of some kind to hold the whole mess together. I've heard of it being screwed, clinch-nailed or rivited but never glued.
And I always thought that a place like the Outer Hebrides, with seawater on every side, would have a wee boatwright behind every rock.

I think some confusion arises as boat builders in different locales don't adhere to a single dictionary of terms. Builders in the area I grew up in on the Northeast Atlantic would refer to narrow planks (Niander notes 1.5" above), tight planked on ribs/frames as strips (no chaulking) in comparison to the wider planks typical of carvel built boats (plank on frame..claulking required).

C'Chuck...just to clarify, how would your expansion theory compare re glue versus edge nailing?

[Cuyahoga Chuck]

You could use steam bent ribs to follow the curvature of the planks, clamp or tack them at the ends, and use your choice of fasteners.



I think some confusion arises as boat builders in different locales don't adhere to a single dictionary of terms. Builders in the area I grew up in on the Northeast Atlantic would refer to narrow planks (Niander notes 1.5" above), tight planked on ribs/frames as strips (no chaulking) in comparison to the wider planks typical of carvel built boats (plank on frame..claulking required).

C'Chuck...just to clarify, how would your expansion theory compare re glue versus edge nailing?

As far as I know edge nailed boats seal by swelling the strips. And because edge nailing can't maintain the strips in the proper shape there has to be ribbing. I don't know how you can glue steamed ribs to strips. A wet rib can be clinched, screwed or rivited but you can't glue it if it's too wet.
As I said, I can't visualize what our Hebridean friend has and what he is trying to do.

[ShagRock]

if i wanna repair by laminating ribs in there do i have to stop the epoxy gluing to the hull with plastic?

I reread Niander's post, and it's possible he means 'building up' the ribs with thin laminates that are epoxied together..not sure..hopefully he will be back to update us.

[RFNK]

My Twister has a splined hull so all planks are actually glued together with the spline and glue as the medium. The ribs are steamed but most are cracked at the turn of the bilge in the mid-aft section. They're riveted to the planking with copper nails and roves. I'll be replacing all cracked ribs with laminated ribs (thin strips of hardwood laminated with epoxy). I'll fasten these with screws simply because I don't want to have to rely on another person to be available for riveting so many nails. I also intend to glue the ribs to the planking as this should help with bedding and also to minimize splitting of seams if I ever need to haul the boat out for a long period again. About 4 seams on each side have opened up now after nearly 12 months out of the water. With edge-glued strip planking or a splined hull, I can't see any downside to gluing the ribs in. The extra strength and stiffening should be beneficial. Of course if the planks are going to swell and shrink a lot then there are going to be problems anyway with any edge-glued planking arrangement and then, I guess, proper sheathing becomes an option. As far as ease of replacing planking later goes, then I think this is a fair point. However, the old planking is going to be destroyed anyway upon removal as it's already glued to the other planks. Cutting the plank away from ribs that it's glued to isn't much of an extra job. Rick

[P.L.Lenihan]

Hi i got this strip planked carvel folkboat so the planks that are about 1 3/4 " wide are all glued together
if i wanna repair by laminating ribs in there do i have to stop the epoxy gluing to the hull with plastic?
and also once the ribs are in place i will have to put in screws from the outside...how far apart would you space the screws ?
the hull is very well glued together still.
cheers

If all your "strips" are glued together, she is strip built,not carvel. You can use epoxy to laminate in as many ribs as you wish and exactly where you want them.No, you do not have to screw them in from the outside.As you build up your laminate of 3,4 or 5 thinnner lats bedded in epoxy, use a few C-clamps with waxed plywood pads to keep the rib laminates aligned while applying downward presure from either temporary braces leading down from the cabin top etc..., or temporary screws driven through the laminates and going only as far into the hull as neccesary to hold the laminated rib in place until the epoxy cures.Begin screwing from the middle section of the rib and alternately work your way upward and downward toward the ends of the laminated rib. Drive screws as near or far apart as needed to get an even bead of epoxy squeeze out all along the laminate seams or faying surfaces. Do not over tighten the screws.Your laminate lats should be thin enough to easily follow the shape of the hull without too much downward force required.

Have fun!


Cheers!


peter

[jackster]

niander,
If it were me, I would replace with what you have.
If bent frames, use bent frames if at all possible. If not possible, laminate them.
If the frames are glued to the planks, then glue the new ones to the planks.
if they (frames) are not glued, don't.
Use the fastening pattern/size existing. Listen to your boat and her builders.
My 2cents worth.

[Mrleft8]

You might want to take a look at this site for an alternative....
WWW.Flutedbeams.com

[niander]

The ribs are in there but some are cracked so im going to sister them with 4mm strips laminated
its an east german folkboat with a smooth hull ....so maybe some one knows the construction method they probably used?...