Replacing Ribs

[Chadd Hamilton]

I am restoring a Lyman 15' powerboat and have removed the original ribs and will soon bend new ones in.

The ribs I removed were fastened with 1 1/4" clinch nails(clinched from the inside out) and I am considering using 1" bronze screws to refasten new ribs. A few considerations as to why I am thinking of doing this:
1. Faster.
2. I can steam and install the ribs by myself without having to rope my wonderful wife into something she'd rather not do.
3. The boat is on a trailer and if reclinching, I would have to get the boat off the trailer and onto jackstands or a cradle in order to access the bottom. Eventually, I'll have to remove it from the trailer, I just don't have a cradle made for it at this time.

These are my pros. I'd appreciate any advice on why this is an unwise decision ect.

Thanks,

[Dale R. Hamilton]

Chadd- I hope you haven't already removed all the broken ribs yet- generally its better to remove one (or pair) at a time, and replace it. This to keep the shape of the hull. If you don't do that, you sure better have a cradle built like an external mold. I like the screw idea- much better.

[Alan D. Hyde]

How about small bronze (or stainless) bolts, with washers under the (holdfast) nuts?

Less likely to pull out than a screw, and less stress on the ribs.

Replicates more closely the effect of a clinched nail, I would think?

Alan

[Bob Cleek]

Before deciding on a fastening option, be sure to consider the size of the frames. A screw will require a bigger hole than a nail, thus reducing the strength of the frame. When nails are used, it is often because they weaken a thin frame less. The best option of all is probably riveting. This will provide a neat, strong connection without the hassle of clinching or any reduction in the strength of the frame. Of course, if you are working with big hefty wide frames, screws are fine.

[Chadd Hamilton]

Dale, actually this boat has 2 different sized ribs. There are, without going to the boat, 8 or so large bent ribs and between these, are 2 smaller ribs(about 20 in all). I've removed the smaller ones, leaving the larger ones(which I'll replace after this job).

Alan, not a bad idea, but again, i'd still have to access the bilge, which is blocked by the bunks, to do this.

Bob, I didn't consider the impact that a larger diameter hole may have on the rib's integrity. In this boat, as I mentioned above, the larger ribs are actually attached by screws from outside-in. But they are thicker in dimension. I think that the by using bronze #4x1" screws(predilled and countersunk) I will be reducing the chance of these smaller ribs cracking or splitting.

thanks again for advice.

[Gary E]

Actually bolts would be easier to install and as strong as rivits without the hassle of peening. I would install the rib and drill from the inside so I could see EXACTLY where the rib and the plank laps are. After snuging up the nut on the washer a sharp center punch is used to make sure the nut will never back off. A lot of Chris Sea Skifs were made this way.

[ 07-11-2005, 03:09 PM: Message edited by: Gary E ]

[Bob Cleek]

Do any of you guys advocating bolts have any idea what everdur bronze bolts and nuts cost? You can't use brass because they will waste away to nothing. If the original builders used clinched nails, I suspect there was a reason and it was because there was no need for anything stronger and they were faster and easier to use. There's no reason a copper rivet is any more difficult to install than a nut and bolt and one thing's for sure, a rivet isn't ever going to loosen and back off like a nut, peened or not.

[Ken Hutchins]

Bob, very well stated.

[Giles]

Copper riveting is easy if you have the right tools, hard if you don't and yes, it requires two.

If your roving iron (the jobbie that pushes the rove down) isn't right the rivet doesn't tigten too well as you hammer it on.

The dolly (the heavy weigt on the outside) needs to be heavy enough to hold against the weight of your initial hammering the roove down and also the bit when you pein over the stub. The dolly also needs the right sized end - ie no larger than the head of the nail.

If your peen hammer is to light it takes ages to peen, if it's too heavy you need stupidly heavy dolly to counteract the weight.

Dunno if there's a step by step guide but;

Drill from the inside out. The drill needs to be a smidge smaller than the across flats size of the (square) nail.
Hold a heavy hammer up aganst the rib, just to one side of your hole.
Inside man shouts ready.

Outside man hammers in nail. The hammer used to drive the nail should be lighter than the one being held up to the rib inside. This ensures the inertia is used to drive the nail, not flex the wood. The nail probably only needs to be flat to the plank... it will pull in later with the dolly.
Outside man holds up dolly against the nail head.
Outside man shouts ready.

Inside man takes rove (or is it roove) and bangs it down over the nail with the roving iron (rove cupped side toward the rib). The hammer for this (possibly your peining hammer ) will be lighter than the one you first used to hold up as the nail came through, and much lighter than the dolly. The rove has to get all the way to the rib (make sure yo're iron has a deep enough recess). Once the rove is down to the rib, a couple more clouts to the roving iron will draw the nail head into the outside plank, and tighten up the joint considerably. The rove will flatten a little as the joint tightens, but it shouldn't flatten completely (hence the need for the correct roving iron). I believe it's at this point that the joint takes up, not when you rivet over the stub with your pein hammer.

As you're hammering down the rove and then drawing the joint together you may be able to hear the process(through your ear defenders of course)... something like thunk thunk thunk thunk think ting tink tink

Inside man shouts clear. This it to give the man on the dolly a rest.
Inside man cuts of most of the exposed nail. I have been told to use a nail laid across the rove as a spacer to cut off to the right amount. I kind of think this leaves you a little bit much to pein over myself and sometimes take a smidge more off.

Inside man shouts ready.
Outside man holds up dolly against nail, shouts ready.
Inside man uses the pein to rivet over the nail stub. You should attack the stub from several angles and several direction to get a nice even smear of the nail stub, and also to avoid walking the rove to one side into the meat of the rib.

Works for me. Fine tuning comments (or indeed wholesale rejection of the above method) more than welcome. I'm not an expert in this matter. By the way... it happens a lot quicker than it reads.

[Gary E]

Giles,
You have described why Chris Craft and I use bolts.

Mr Cleek, you can do whatever you want.

[Bob Cleek]

Riveting is easier done than said, actually. I know that a lot of fellas will get their feelings hurt reading this, but there's no dispute that much of Chris Craft's production was NOT well built. (Ask anybody trying to restore one!) They were production boats intended for a short lifespan with little thought given to the sort of ongoing repairs necessary to keep a wooden boat going forever. If they used nuts and bolts (which I've never seen, but stranger things have happened) to hang plank on 15' power boats, they must have been smokin' something. You want to bet on a race between an experienced riveting team and a somebody putting nuts and bolts together? My money is on the riveters. It's a hell of a lot easier to buck a rivet and peen the nail than it is to have one guy turing a screwdriver or wrench with another guy inside holding the nut.

[Bob Smalser]

Seems to me they aren't bolts til their guarter-inch or larger.

You're talking about #8 or #10 machine screws, which I wouldn't do because of 1) Way too much trouble 2) Expense and 3) Ugly.

Your planks likely aren't thick unuf to cover fasteners with plugs, so I'd be looking at 8, 10 or 16D copper common nails with burrs riveted over. Driven in from the outside, of course.

Unlike clinch nails, you don't have to do a rivet all at once. Once the pilot hole and nail are driven, the assembly is usually tight enough (if you did it right...use a calipers to measure nail/drill diameter and wire gage drills to get tight fits with your nail shanks) to wait til you're ready to nip and peen....and you only need a helper come nip-and-peen time.

[ 07-11-2005, 10:38 PM: Message edited by: Bob Smalser ]

[Noah]

Wait a minute...Lyman's are "Clinker Built." It's part of the way they are done. Don't go changing this aspect of the boat. Ours is a 1957, and it has never really leaked a drop despite a bunch of years of neglect and hard use (before my time).

Also, Lymans are getting collectible. They generally demand a higher price than other similar boats, and it's for a reason. If you want to retain that value keep the boat the way it was built. I saw a Thompson that someone had used bronze nuts and bolts on, and it looked like hell. Furthermore, these boats don't use a rivet and washer that's peened over. They use something more like a boat nail that is bent back over. I bet it will go pretty quickly.

Noah

And a couple of pictures just to help...

http://www.morebutter.com/images/woodchuckgoingfast.jpg http://www.morebutter.com/images/woodchuck.jpg

[Noah]

Ack!! Really, the more I read this thread the more there is wrong with it.

Lyman's don't use a standard rivet with a rove!! All of the "experts" here need to go take a look at one of these boats in question, then realize they are giving really bad advice. The 15' Lyman has very small ribs, and pretty thin planks. It's a light boat. The "rivets" need to be a very small gauge so not to destroy the ribs.

Chadd, go to one of the Lyman forums, and talk to owners there. Listen to what they have to say. Next some wanker here will tell you to use galvanized boat nails cause they worked well in his trawler 75 years ago.

[Steve Hornsby]

Check out Koroknay's Marine Woodwording site for additional thinking on Lymans. There is a question and answer feature with a search function.

Steve

[Domesticated_Mr. Know It All]

Chadd.....What Noah said. There is a process called "reclinching" that is basicly tightening the bronze screws and clinch nails to keep the planking tight to the frames and each other. It's the fasteners that hold the boat together(and make it watertight) not the goop you put on later. It's the most important part of any Lyman restoration in my opinion. It's a pain in the ass, takes 2 people and is time consuming but is the key to a seaworthy, dry, "clinker-built" boat. Steve's good advise is the same website I e-mailed you a few days ago.

Some photo's of a front steering 1950's 15 footer.....

http://www.lymanboat.com/raphael.jpg

This is the interior set up for the "rear steer" model....

http://www.lymanboat.com/jenkins2.jpg

Some had windshields and some didn't.

[ 07-12-2005, 07:03 PM: Message edited by: Mr. Know It All ]

[Domesticated_Mr. Know It All]

Cool little boats eh? :D

http://www.antiqueboat.com/boats/images/veli17-4.jpg

[ 07-12-2005, 07:17 PM: Message edited by: Mr. Know It All ]

[Alan D. Hyde]

Nice boats, Mr. KIA. :D

Good advice, Noah. An authentic restoration is always preferable, often for engineering as well as for esthetic and value reasons.

I only suggested bolts because he seemed dead set against the original method. Bolts have been used successfully by several large-scale lapstrake builders. I don't recollect right now what Skiff-Craft uses, but a Skiff-Craft guy, Bill Berrisford (IIRC) is a sometime poster here.

Alan

[ 07-13-2005, 12:07 PM: Message edited by: Alan D. Hyde ]

[Domesticated_Mr. Know It All]

Bolts and nuts might have been used on other plywood lapstrake boats like Thompson or Cruiser's Inc. among others. I seem to recall hearing that. I've heard that rivits have also been used successfully. The important thing is to tighten her up while the paint is off. Many people overlook this step and later try to fix the leak with goop. Take the time now (to reclinch, refasten or reglue) and save yourself the headaches later.

[Bruce Hooke]

WAIT A MINUTE HERE FOLKS:

Point #1: As Chadd said right near the start of this thread, bolts won't solve his problem because he does not have good access to the OUTSIDE of the boat right now (it is on a trailer). Anything that requires access from the outside is a problem.

Point #2: I am, therefore, concluding that he is talking about using screws installed from the INSIDE (is that right Chadd?). If that is right then NO THIS WILL NOT WORK. Screws need to go from the outside in. The holding power of screws driven through the ribs and into the planks is VERY limited. So, you are going to have to wait until you can get access from the outside.

[Chadd Hamilton]

Thanks guys for all the input. I've mulled it over, and will just refasten with the clinch nails. I should be able to clench most of the ribs(minus the bunk areas). When I get the boat off the trailer I can just finish up those areas. Should work out just fine.

Thanks again.

[Bruce Hooke]

Sounds good. When the rib is hot out of the steambox you usually just need to get a couple of possibly temporary fasteners in place to hold the frame while it cools. Then you can come back later and fill in the other fasteners...

[RonW]

Hold it. Clearification.
Which probably needs answered by Noah or Mr know it all, or some one that knows lymans.
Are these clenched nails squarish in shape and have a chisel point, kinda like a small concrete nail. If so where they soft iron or are they copper.
I think that is what they are, and if so where in god's name do you get them????
Jamestown and hamilton are selling the old time square boat nails with the bulge before the head, but these are hot dipped galvanized, and you can't clench them, just because clenching will break the galvaniziation and they will rust. So what you need is the old time iron or copper, and again who sells these in todays world???

[Chadd Hamilton]

You can get the duckbill type clench nails from Tom Koroknay aka "Doc Lyman", or you can get them here: http://www.slateandcopper.com/copper_nails_page.htm

[Domesticated_Mr. Know It All]

Chadd......This is a very informative good read by one of our forum members, his book is a must read too. ;)

http://www.danenbergboatworks.com/lapstrake.htm

[RonW]

Allright, shake the tree a little and look what fell out, some good info and websites. I saved both sites, good deal.

The copper site has some clench nails all the way up to 1 & 7/8 , these are not very easy to find.
And I will admitt that I didn't even know that they made ring shank boat nails in copper.
But most of this stuff is coming from finland, sweden, norway and such where they still use copper fasteners and so forth.

It has been a long time since I have seen half round copper gutters. This is serious bucks that even loose spending good natured rich folks, don't like to pay for.
Good copper site, erie pa. isn't that far from here.

[Domesticated_Mr. Know It All]

I found another nice photo.... :D

http://www.classicboat.com/ad-lyman.jpg

[RonW]

NICE? How about VERY NICE....

A year ago I examined the almost twin to that boat, but it wasn't made by lyman. It was sitting at all places at goodwill. Someone donated it, and it was sitting on a trailer half full of water with ropes tied around it to keep it from bulging and splitting, it never leaked a drop.

The metal tag on it said it was owned by the state of ohio park division in 1958, which has been deflunked for a very long time.The lapstrakes where 3/8 thick douglas fir marine in 5 ply, with white oak ribs. The ribs where spaced a lot further apart then in your picture.
It was riveted on the frames and clenched nailed with copper in between the frames.

It was actually in good condition all but the decking and trim which was mahogany plywood, and all the mohagony ply was rotten and delaminating.
I have many times examined ply boats from the 50's and every time the douglas fir ply is excellent, unless around the transom where it sits for years with water, and the mahogany plywoods (used for trim) are always rotten and delaminated badly.
So much for paying high dollar for mahogany plywood.

I have also seen boats from this era of ply lapstrake with brass, not bronze, round head machine screws and nuts. The nuts did not have washers under them, but the end of the little bolt just barely stuck past the nut, and was then peened over like a rivet. So they where going no where, and these where brass, but it was intended as a freshwater boat.

[ 07-16-2005, 06:57 AM: Message edited by: RonW ]

[Domesticated_Mr. Know It All]

Great post Ron. ;)
I sure wish I could find some more of the "old growth" Douglas Fir plywood Lyman used in 1961.
I'd be tempted to replace all the mahogany ply and White Oak with it, even though it doesn't look as nice varnished. Painted it seems to last forever. :D

[Domesticated_Mr. Know It All]

One of the few wooden boats at the Mid-American (Plasticrama :D )boatshow in Cleveland, last winter. A nice little woodie in a sea of fiberglass. :cool:

A 1950's Lyman 15 footer....

http://www.imagestation.com/picture/sraid155/pd0f726b42d3abdc1ded85699308a793f/f55bef7e.jpg

The LBOA has a much better (in the water) show with close to a hundred wooden boats next month in nearby Huron, Ohio.
Another good website for Lyman's....

http://www.lymanboatownersassoc.org/

[Domesticated_Mr. Know It All]

Lyman didn't just mass produce wood fishing boats, they made one of a kind boats of any design, for anybody with the cash. ;)

http://www.lbsna.org/agora/getfile.php3?bn=lbsna_photo&key=1073499532

another good Lyman website with a forum......

http://www.lbsna.org/

[Andreas Jordahl Rhude]

Chadd, the best advice you can get for this Lyman is from Tom Koroknay AKA "Dr Lyman." Thompson and Cruisers, Inc. and T & T Boats, Inc. and Grady-White Boats all used screws to fasten the plywood lapstrake planking to the ribs. Machine bolts/nuts were used to fasten the planking to the adjacent piece, between the ribs. Between each rib there were three below the water line and two above. I have chatted with folks that have had to disassemble a small Lyman and then have seen a Thompson and wish Lyman had used the screws and bolts, lieu of clinch nails. Andreas

[Paul Morris]

An interesting and useful variation of bronze nut used in some planking and repair applications is the "PM" or "self gripping" nut. These can be gotten thru Clark Craft Fasteners (www.ccfasteners.com).
Also really good copper clench nails can be gotten at Faering Design co. in Vermont. (www.faeringdesign.com ). ;) smile.gif
Paul

[Paul Morris]

An interesting and useful variation of bronze nut used in some planking and repair applications is the "PM" or "self gripping" nut. These can be gotten thru Clark Craft Fasteners (www.ccfasteners.com).
Also really good copper clench nails can be gotten at Faering Design co. in Vermont. (www.faeringdesign.com ). ;) smile.gif
Paul