View Full Version : Laminated Sisters (Apologies to Cleek et al)

Larry P.
05-23-2002, 01:04 PM
With apologies to Mr. Cleek and the other traditionalists (I' usually with you guys). I have 3 cracked frames on the port side of my SS Sloop. I was contemplating laminateding sister frames in place. This would be temporary, for this season (I'm hoping to race her this season). Over winter I plan on replaceing them with sawn or bent frames. Any suggestions on the best material for laminated sisters ie ply, mahogany, oak etc.
Also when I do replace them I want to use original material. These frames are from sawn hackmatack, does anyone know of a source???


D***M Those red x's I give up on the photos :mad:

[ 05-23-2002, 02:38 PM: Message edited by: Larry P. ]

05-23-2002, 01:12 PM
I fitted some replacements (not sisters) to my clinker boat this winter using white oak strips and resourcinol. They were a bit of a ba***rd to fit but the end result was good. I imagine it would be easier if you were using an existing frame to clamp them to.
I don't think traditionalists are too much against laminated frames or sistering - both have been around for a long time and are well proven.

05-23-2002, 01:43 PM
If the sistered frames are only temporary, use whatever is cheap and at hand - laminated fir would be fine. As for sourcing Hackamatack, I believe there was a thread in here earlier on that topic with addresses of suppliers in Maine. If you can't find the thread, an article in WB sometime in the past year featured a fellow in Maine who supplied such stuff.

05-24-2002, 06:29 AM
Hi Larry,
If you want to use steamed sisters I'd be glad to help. If you have your boat on a trailer we could do them at my shop in Babylon in a few hours. If you want to laminate them use either doug fir of mahogany as they both glue well with epoxy. The boats built in the 60's used 1" mahogany plywood frames and several of the boats I've worked on had sisters sawn from this. I'm not a big fan of plywood frames but they seem to hold up okay on these boats. If you are just trying to get one season out of this repair you might just glue and screw plywood to the side of the old frame and avoid the extra holes in the planking.

Bob Cleek
05-24-2002, 12:58 PM
Nothing wrong with laminating frames if it's done right. You can use oak strips with epoxy, which is easier than resorcinol, which requires stronger clamping. (You can staple the epoxied strips one on top of the other.) If you do a neat job replacing a frame, rather than sistering, and finish it nicely, you can hardly tell the painted laminated frame from the steamed or sawn one... the steamed and sawn ones will be the ones that are cracked! LOL

Jim Lowe
05-24-2002, 01:50 PM
Here’s another approach Larry. (Sorry, I couldn’t get Sam Manning on such short notice).
This requires clear access to the frames to be able to dish out the area above and below the break with a disk sander or spoke shave (I'd try to get at least an 8:1 ratio on the lenght of the arms). Taking full advantage of the gap filling and low clamp pressure requirements of thickened epoxy, laminate thin strips to bridge the gap and build up the area again. You can lay the strips in one at a time and use staples to hold them while the epoxy sets or build a form and brace from the overhead if you want to try and do all the laminates at once. Fair up the area after the cure and refasten using the original holes.
Should make a reasonable temporary repair till you can bend in replacements without having to make new holes.

05-24-2002, 02:29 PM
Larry, are the trailer bunks under the cracked frames?

[ 05-24-2002, 03:29 PM: Message edited by: TomRobb ]

Alan D. Hyde
05-24-2002, 03:02 PM
I had a friend who got in bed with some laminated sisters once.

Had a good time, too, but his wallet was gone in the morning.

What? Oh, nevermind...


Bruce Hooke
05-24-2002, 03:57 PM
I looked at the photo:


and I just wanted to note that if those are in fact sawn frames then either the joints between the sawn sections are well hidden, or someone found some boards with just the right arc in the grain (unlikely), or there must be one heck of a lot of grain runout in those frames and it's no wonder you are having problems with the frames cracking. It's a little hard to figure out what's cracks, what's grunge, and what's planned joints, but it looks like there might be some cracks that point to grain runout. These frames really look to me like the good candidates for steam bending or laminating, rather than sawn.

One other thought -- how much time will you really save by sistering with laminated frames rather than yanking out the broken frames and laminating in new frames to replace the old ones? That way you would save having to drill new holes in the planks and the job would be done...

Hmmm...for some reason the link I had to the photo didn't work, but if you copy and paste the link into a new window then you can get to the photo. I'm guessing that GeoCities is trying to stop people from linking to photos posted on their site from other pages outside of GeoCities. Many ISP's do this to cut down on the load on their server. This would also explain why you are getting a red X.

[ 05-24-2002, 05:01 PM: Message edited by: Bruce Hooke ]

Larry P.
05-24-2002, 09:44 PM
Thanks for all of the advise guys. Tom you hit it on the head all of the cracks are over the bunks, when I found her she was sitting in the back of the marina, with about 4" of water inside. The cracks are right where the port trailer bunk is. I'm hoping to get her off the trailer and into a cradle this weekend. This thread was worth it just to see Mr. Cleek talk about epoxy :D

Hugh Paterson
05-26-2002, 07:17 PM
The replacement laminated frames if done right will be stronger than steamed frames as well, always a good point to consider :D