Small Thames Boat Repair

[TopT]

Hi guys, finally getting round to refitting the bent frames on my boat. Ordered the green oak and its concetrated my mind somewhat.
Sadly on closer inspection the carvel planks are giving out at about amidships, if thats the term or at the wide bit!.
Previous owners repair was to caulk the split. The rest of the planks are close fitted with no caulking, so whats best thing to do. Dont really want to bend new frames into an off shape hull. As you can see the frame has lost its full rounded shape and probably cracked at the bend.

Tony.

[Thad]

Your impulse is correct. Much depends on plank fastening. Cracked frames straighten. Space will have opened under the floor. Cutting the frame away and cleaning under the floor as well as reefing the seam will allow the planks to be pushed back fair. Then new framework will hold the planks tight and fair.

[TopT]

Thanks for that, I made a start yesterday on clearing the caulking. I suspected that I will have to put more work into the job. You make it sound that the planks will go back, so I'll pursue that route. The boat dates from the 1960's I guess, so bound to need some reworking.
Tony

[TopT]

Looking better already, every other frame was already removed, so I cut a 1" chunk out of the existing frames from aft to centre section at the unwanted chine point. The whole loose section now pushes up easily to close the now reefed gap. I think its going to work out ok.
Tony.

[Thad]

And it will! Good.

[TopT]

Oh dear, not going so good. Made a steam box and fired it up for an hour with new frame wood. Attempted to part bend it on knee and insert inside, - broke and there seemed a nasty twist at the break point. Made a boiling tube from 2" piping and heated with propane torch for 45 mins. Made a former to the size of inside of old frame with a chipboard base screwed to it, also fixed several blocks to drive a wedge in to keep the shape. Tried a test piece which had a knot halfway up, - it broke. The remainder bent fine. Selected a good looking new piece heated it up and tried again, this time I nearly got it completely around, but it broke at hidden knot.
I'm not confidant of the knowledge of the supplier, so I think I will have to order from an understanding wood supplies Co.

Tony.

[TopT]

Just a bump to say things are moving ahead. Took a while off to get over man flu, re-tried the bending with the correct wood and having good results, not one broken yet.
I made a former from 2 squares of chipboard and shaped one to the form of inside the old rib, then bent the ribs on the bench. The former was cut with an angle on the jigsaw blade to give some twist to the rib. So far one jig suits all the ribs up from stern to midway.
My arms are not long enough to get all the way in with the nails, so going to have to get some help with that.
Tony.

[TopT]

Frame fitting is coming towards the end now, so turned boat over and to start fixing broken plank, which turned out to be 3 sections required.
Had some wood machined oversize and cut the first plank taking time to achieve a 15 thou gap either side, looking good.
Made a makeshift jig and cut a perfect but/scarf joint - looking even better!. I need to get some twist and bend in the plank, so soaked it overnight and steamed it for 40 mins and clamped it to the next board to get some form into it. After cooling the plank is 4mm oversize on the width! so cant go any further just yet. Certainly didn't see that coming.
Advice please.
Tony.

[Peerie Maa]

Frame fitting is coming towards the end now, so turned boat over and to start fixing broken plank, which turned out to be 3 sections required.
Had some wood machined oversize and cut the first plank taking time to achieve a 15 thou gap either side, looking good.
Made a makeshift jig and cut a perfect but/scarf joint - looking even better!. I need to get some twist and bend in the plank, so soaked it overnight and steamed it for 40 mins and clamped it to the next board to get some form into it. After cooling the plank is 4mm oversize on the width! so cant go any further just yet. Certainly didn't see that coming.
Advice please.
Tony.

Leave it clamped in place whilst it dries out a bit. You may have increased the woods humidity way above that of the rest of the boat. When it has had a chance to stabilise you may find that it is closer to fitting.

[TopT]

Replaced 3 broken sections eventually and now have all planks and most frames replaced. The worst case gap was 0.080" between planks, I think thats the best I could get considering its age and past maintenance.
Looking at the keel its had a hard life, some of the coach bolts are steel and a few bronze. The coachbolts seem to be lifting out of the keel, or maybe the wood is deteriorating around them. I think the quickest cover-up job is needed here or it will never get into the water. Whats the easiest way to get around this, and for the future whats a good repair job entail?, say capping with a metal bar - easy for me, adding a new edge to it, harder for me.
What primer do I use red oxide, how many coats, whats an acceptable top coat below w/l , its going to be lifted out daily so no antifouling required.


Tony

[Peerie Maa]

You should order some new bronze coach bolts, the steel ones will deteriorate and may well damage the keel.
See if there is a local supplier for these http://www.teamac.co.uk/ near you. They used to sell read lead paint, which it looks as though was on her bottom. As to the protruding bolt heads, I'd plant a keel shoe on, with scoops cut out with a gouge to clear the bolts. Bed it in putty and screw it with silicon bronze screws and all should be well until you want to spend more time on her. You should then cap with keel banding. You may get all you need, bolts, screws and banding from http://www.classicmarine.co.uk/

[TopT]

Thanks for the reply Nick. Had a good look and a think and a price check. Bronze is silly money in the UK, much better in USA so could get a friend to bring me some in, even so 5/16" x 7" are not easy to find. The steel carriage bolts fitted are original and they have lasted for 40+ years, so maybe put a shoe on and replace with steel. I am sure now that the 10 or so bolts were intentionally potruding to protect the keel bottom when hard standing. Could even use the same bolts if they come out ok. I could make them up from brass though, what would be the downside of using brass for river use only?.
Tony.
misunderstood slightly, you were suggesting capping the whole old assembly, where'as I was thinking trimming the old keel down and rebuilding as was with a new shoe added. Have to have another think.

T.

[Thad]

So, if you wanted 5/16 x 7" SB carriage bolts and SB screws (what size?) how many?

[Thad]

Price for one box of 25 at Hamilton Marine is $205.31.

[Peerie Maa]

The bolts will not have been left protruding, that would be bad practice. I would replace the steel with bronze or copper. If you don't fancy bronze coach bolts use copper headed up over copper or bronze washers.
If you were to cut the old keel down and glue on a replacement you will need to take all of the bolts out anyway. You can then counter bore into the new piece for the bolt heads and washers if you don't use coach bolts. That would take longer though.

[Thad]

Copper is good.

[TopT]

Done some more looking and thinking, and probably will bite the bullet and replace a couple of inches along the keel. I was impressed with the reasonable price of the 25 bolts. I will need a selection about 10 from 7" down to 4". Found another supplier in Belgium whose 7" bolts are about £4, that compares to Davey's UK price of > £20 for a 5" one!!. I will email them and get a current price. They dont call the UK treasure island for nothing!.
I will make a start to remove the old bolts today and try to get some inspiration.
Thanks for the input guys.
Tony.

[gondolier88]

Have you thought about buying bronze bar and threading it yourself- it's even cheaper, and you can pick up UNC, BSF or Whitworth (depending on your preference) dies from all sorts of cheap places. You would just need the nuts then.

Metals4u is usually pretty good at supplying bronze- however most metal stockists keep bronze bar upto 3/4" in stock, if you have one nearby it might be worth getting in touch, they may also stock dies to suit.

Greg

[Peerie Maa]

Done some more looking and thinking, and probably will bite the bullet and replace a couple of inches along the keel. I was impressed with the reasonable price of the 25 bolts. I will need a selection about 10 from 7" down to 4". Found another supplier in Belgium whose 7" bolts are about £4, that compares to Davey's UK price of > £20 for a 5" one!!. I will email them and get a current price. They dont call the UK treasure island for nothing!.
I will make a start to remove the old bolts today and try to get some inspiration.
Thanks for the input guys.
Tony.

Have you thought about buying bronze bar and threading it yourself- it's even cheaper, and you can pick up UNC, BSF or Whitworth (depending on your preference) dies from all sorts of cheap places. You would just need the nuts then.

Metals4u is usually pretty good at supplying bronze- however most metal stockists keep bronze bar upto 3/4" in stock, if you have one nearby it might be worth getting in touch, they may also stock dies to suit.

Greg

Making your own is a really good option, as you can cut the threads to just the right length. You will need a slightly deeper counter bore in the new piece of keel for the new bolts than for the old bronze coach bolts, which I assume you can re-use. That will not be a problem though. Don't forget to peen the end over on the nut on the outside to lock it in place.

[TopT]

I have plenty of dies and taps in the w/shop, so thats probably a good way to go, I can also turn up some dome type head pieces for authenticity, just grind the square part to shape. Looking cheaper by the minute.
Removed the longest bolt, took about an hour. I'm going to turn the boat today and finish off plank and framework before re-turning it for completing the underside.
Any idea what originally went on the bow? there is a flat all the way around it and there is a piece of ali screwed to front of keel, see pic. Thanks for the ideas by the way.
Tony.

[Peerie Maa]

I have plenty of dies and taps in the w/shop, so thats probably a good way to go, I can also turn up some dome type head pieces for authenticity, just grind the square part to shape. Looking cheaper by the minute.
Removed the longest bolt, took about an hour. I'm going to turn the boat today and finish off plank and framework before re-turning it for completing the underside.
Any idea what originally went on the bow? there is a flat all the way around it and there is a piece of ali screwed to front of keel, see pic. Thanks for the ideas by the way.
Tony.

As you are going to cover the heads of the bolts, you do not need to be too precious about replicating coach bolts. If you want to keep them skinny, you may need to braze the heads onto the threads for strength.
If there are empty screw holes along the stem she will have has a stem band, either wrought iron or brass half oval.