1948 I14 mast for Tiptoes No.521

[Fantasia]

I am about to start the restoration of Tiptoes and have decided to begin with the mast. The mast is original and complete; but the construction joint that runs up the middle has partially come apart.

I intend to remove the rigging and fittings for later re-use, seperate the mast into its two halves, check the joint, and reglue it, before revarnishing and refitting the fittings (winches, sheaves, etc) and rigging.

I have a question: does anyone know how the spreaders and sheaves are attached to the mast? For instance the sheave for the mainsail halyard runs on an axle that passes through the mast and there are washers on the outside and it appears that the axle is rivetted over onto these. How does this come apart? Do I need to grind the end off or is there a better technique? The spreaders also seem to pass through the mast.

Mast is now in the workshop and investigation begins. I'll let you know what I find and will post images in due course.

Many thanks in advance, John

[JimC]

...it appears that the axle is rivetted over onto these. How does this come apart? Do I need to grind the end off or is there a better technique? The spreaders also seem to pass through the mast.

That sounds feasible... If you can replace the pin then just lopping the end off is good: watch out for heat of course. If I didn't have a new one in front of me (and make sure you can get one otherwise youll need a sailor friendly engineering shop) I might try de-riveting it back on one side, but it would be one soneofabitchofajob because it will be so difficult to get a second drift or something on the other side so that the hammer blows don't go into the mast.

Spreaders - you'll have to suck it and see. I have seen two techniques used in the past. The Bethwaite wooden Cherub wing mast has titanium (honestly!) tubes as spreaders which rest on the wood with a pin through the mast the spreaders rest on. These just come apart with care. I've also seen a needlespar setup which used a single solid alloy rod all the way through with a alloy collar each side. The collars were held in place by a sort of cotter pin which went through a hole drilled through collar and rod, which was just riveted over into a counter sink at the ends and filed smooth and almost impossible to spot. Removal was to drill out the riveting in the countersink then drift out the pin. Both these are early seventies vintage though.

[Ed]

In my experience of this.....mainly with a Fairey hollow wooden mast...

the tubes that go through the mast don't have any glue, they are just put through the mast, with a washer either end and then have the ends knocked over to make them into a big tube rivet.

I think you are right. Grind them off, tap them out and then replace with similar tube afterwards.

The spreaders that I have removed have likewise had no glue in them, they have just gone through the mast and had a bend put in them just outside the mast on both sides. I couldn't see anything else holding them there (although now that Jim reminds me - I have seen those little cotter pins too). They can be a pain to remove, you have to cut them either just outside the mast, or in my case the mast had opened up enough to get a hacksaw in and cut it in the middle. I think the chances of getting them out without breaking are low.

None of the other bits were glued in.....winches just dropped out when mast was separated.

Fixing the mast halves back again is an interesting job and one which has been done by many CVRDA bods, so I will let someone else make a start on the instructions on that. But my memory is simply that you can not have enough clamps/bands.

cheers

eib

[JimC]

I... I will let someone else make a start on the instructions on that. But my memory is simply that you can not have enough clamps/bands.

Isn't that always true! I've got that job somewhere in the future as there's a two piece 11 plus mast in the garage. I'll tell you what though, I'm wondering whether heat shrink tape might be a good call for that job as being less prone to damaging the wood than the more mechanical means.

[Obscured by clouds]

if you intend epoxying the two halves then although you need to clamp the halves, you don't want to much pressure.

the best way I've seen hollow masts glued up are as follows:

Coat both faces with unthickenned epoxy and let it kick, then butter up both sides of the mast with moderately thickened epoxy and use a jubille clip at the widest spot tightened just enough to hold the halves together. Then add a spiral of waxed string - about 3 turns to the foot along the length to hold the rest together. add another jubillee clip at the mast head and one at the foot. One person turning the mast whilst the other pays the string is the most effective way.

there should be enough tension in the string to hold the halves together, but be flexible enough to allow you to block and brace the mast so that it runs straight and true.

Of course if you go down the cascamite route you will need LOTS of clamps - all you own, all you can beg, borrow and steal. and then a few more.

[Fantasia]

Progressing well already and thank you all for your replies. The tubular fixings are indeed rivetted/swaged/peined and I have removed these filing of the end and then making a drift and knocking them out. I shall have to make replacements for these and other aluminium parts that have fizzed. One of the spreaders at jib/spinnaker halyard height was threaded right through the internal fitting and simply unscrewed. The other two pairs of spreaders are simple ali tubes, pushed through a peined over sleeve and then slightly bent to stop them coming out. These have corroded together into a nasty mess and I fear that they will have to be sacrificed to remove them and replicated. I shall do the metalwork myself and shall probably use aluminium again for authenticity, although I know its limitations in the galvanic scale when mixed with sea water.

I am told that Uffa Fox's builders used scotch glue (hot animal glue) to join the masts originally and I shall find out shortly if that was true. Although I am used to using hot glue for veneering I think that I shall probably use epoxy this time. I have more than enough cramps, but I am aware of the danger of distorting this hollow spar. I might use a combination of a few cramps with shaped blocks and strips of lorry tyre inner tube wrapped around in a similar way to the string method described above.

Anyway back to it, as I want this to be a swift and pragmatic job without too much dithering. I might start the hull next week and so I am bound to be back with more questions.

[alan williams]

Hi I've used the Inner tube method at least 4 times back in the wooden mast days of Enterprises and Hornets works really well.
Hope job goes well.
Al

[Garry R]

I'll pass this tip on but of course acknowledge that it was Chris Barlow who advised me. Get an old car inner tube and cut a long 1/2" wide strip from it. Best way is to cut across the tube and then cut a long spiral out of it - I think that I cut one out about 5ft long. Then when you glue up wind the rubber around the mast in a long spiral stretching it very tightly. Being rubber it doesn't mark the wood at all. I also found that if you wanted to use clamps then a looser wrap of the rubber provides an excellent grip for the clamps which I find slip off wood on its own. Don't forget the danger of getting the halyard stuck in the new epoxy glue been there, done it got the T-shirt.

[Ed]

It sounds like you have it under control John!

lots of bands, a few clamps - not too tight is the way to go.

and of course:

Keep it straight....and mind the halyards (yeah done that one too)

I have found the hardest thing has been keeping it....or getting it straight (if it started bent).

do take lots of photos and report back.

cheers
eib

[chris]

All I can add is about the tightness of rubber (or cramps come to that. ) If the rubber strips are too tight they will close up the luff slot or even break it. If cramps are too tight they might open up the slot if applied to the hollow center of the mast.

I wouldn't consider cascamite.

Wax or vaseline a nylon scrap piece of rope (bailer twine etc) to lay down the centre to pull the halyard through later.

Glue it up dead straight!

The original aluminium spreaders etc were probably made of Duralium which was developed for the aircraft industry then. It's strength is closer to a mild steel than ordinary ali alloy which might be on the weak side. If you manage to source some please tell us where.

[JimC]

to pull the halyard through later.

And <eggsuckingmode>I suggest its a good idea to pull the messenger line to and fro a few times before the epoxy goes off...</eggsuckingmode>

[roger]

The original aluminium spreaders etc were probably made of Duralium which was developed for the aircraft industry then. It's strength is closer to a mild steel than ordinary ali alloy which might be on the weak side. If you manage to source some please tell us where.

Yes please do. Although the new alloy ones we made for Shoestring coped with the winds at Bough Beech

[Fantasia]

The spreaders look very like aluminnium rather than duralumin and as I do not know where to source duralumin fron, I shall replace in ali (and prob make some spares). The sleeves through the mast are brass.

Proper work interrupted and I only returned to the mast today. It is now in two halves. I separated it by tapping in low angle softwood weges into the open joint and injecting the joint with meths. Lots of wedges and meths later it was separated and remarkaby intact. There are several scarf joints in the lengths and one or two of these have been reglued today. The faces are cleaned-up and the internal halyard winches restored so that they run freely. There was very little evidence of the previous glue, but I think that it may have been aerolite, which I remember using in woodwork classes as a kid (1960's).

The internal and external shaping of the mast is a work of art. I shall take every care not to distort it and to keep it straight when re-gluing and I note the cautions about halyards being glued too! The spinnaker halyard exits through a very simple hole at the bottom of the mast, without a sheave.

[Mungo]

For modern equivalents to Duralumin try the heat treated aluminium alloys 2024-T3 or 6061-T6. Both have substantial tensile strength, particularly 2024. 6061 is more corrosion resistant and weldable but 2024 is stronger and available clad with aluminium. Both should be readily available from a metal shop in many shapes and sizes and are not too expensive unless you want large thick pieces. Used to make planes, microlights (2024) and,... boats (6061). All that from a lucky conversation with my university machine shop the other day when I asked for a scrap of metal to use as a shim....

[Keith66]

Regarding glues on wooden masts, originally a lot of the spar makers used Casein glue which is a milk by product, though adequately strong it tends to come apart if it gets damp. They may also have used Beetle glue an amino formaldehyde. I would doubt if they ever used scotch glue as its a hot process & i cant see how you would have time to use it.
I would not use epoxy on a spar for the reason it has little or no ultraviolet restistance, regardless of how many coats of varnish go on top it will degrade & start to fail, you will see the epoxy start to go gingery in colour, once this starts its too late.
The best glue for spars is still Aerolite 306 or its modern equivalent, though its a urea formaldehyde based glue like cascamite it is far superior & has very high UV restistance.