crooked mast

[ddeaton]

Ok, I am trying to save a 27' mast for a gaff rig cat. It was carved 20 yrs ago and was never finished. It has about 3-4" of bow in it. The eyebolts and bolsters are mounted so that the bow would be to port side. With no side stays, should I remount all items on the mast so it will lean towards the stern and tighten up the forestay to take it up?
Thanks
Danny

[Lewisboats]

Originally posted by ddeaton:
Ok, I am trying to save a 27' mast for a gaff rig cat. It was carved 20 yrs ago and was never finished. It has about 3-4" of bow in it. The eyebolts and bolsters are mounted so that the bow would be to port side. With no side stays, should I remount all items on the mast so it will lean towards the stern and tighten up the forestay to take it up?
Thanks
DannyBuild a steam box and steam the bow out. a 10 ft box should do, and use some weights over a pivot point to straighten it a bit at a time. Kinda like straightening a natural wood arrow shaft.

Steve

[Ian McColgin]

Well, you have four or five months before you're sailing. Especially if it's an even bow caused by faulty storage, try mounting it firmly - you'll two clamps at heel and truck and one opposing at the apex of the bow - to take the bow out and maybe overspring by an inch. Check each month reducing the overspring as the mast approaches straight.

Your Plan B of turning the fittings is possible only if the mast has an utterly symetrical taper. Look very closely as a righteously tapered round mast is deceptive and will have the taper on the sides and front only - straight luff. That straight luff is something you want to keep as you take the athwartships bow out.

G'luck

[ddeaton]

The bow is close to the base, just starts where the octagon tapers to round. Like you said, I had to look at it a few different ways to figure it out. I sighted down the joint where the 3 boards are glued up and pulled a string along the joint from the base. That is where I got the 3 to 4". The bow seems to be at the thickest part of the base, I dont know if just hanging weights will work. I am planning on building a steambox, but that will be later in my next project. I am currently stripping the old varnish now. I guess the shims wont have enough room to make up for it?

[ddeaton]

Ian
I will look closely at the taper. Thanks for pointing that out. So much to learn! That is why I ask.

[Ian McColgin]

Interesting that it's near the base. I take it that the shift from round to square is just below the partners (round hole in the deck) or just above (square hole). It's likely that the mast tapers below this, facilitating stepping. And this is where the bow is??

Especially in an unfinishde mast, this could well be some unequall seasoning over the years, putting the bow right where the most change in the mast's dimensions.

I still would expect that clamping it securely in a cold bend will work just fine and you can easily put off steaming such a stick till later anyway. If you must steam, perhaps a duct taped up styrofoam box can easily be sealed off above the bow so you're only steaming 10' or so.

[Gary E]

Your the boss...

push it where ya want it...

http://www.savagepress.com/straightening/images/st4.jpg

Actually maybe you can see the idea of applying pressure where that press does and use the idea to make something sturdy of 2x12's and use it like the press.

[Nick C]

You can cut your sail to handle the bow. If the bow is visually noticeable, just tell folks it's an improved design used by an obscure ancient fishing tribe that creates a more forward draft and allows the vessel to point higher.

[Gary E]

Originally posted by Nick C:
You can cut your sail to handle the bow. If the bow is visually noticeable, just tell folks it's an improved design used by an obscure ancient fishing tribe that creates a more forward draft and allows the vessel to point higher.yeah... so much for improved design ...
they is so "obsure" they is all D E A D .. :D

[ddeaton]

Ok, more dumb questions. On the gaff rig with hoops on the hoist, is the mast tapered only 1 side?
The plans call for taper from the boom gooseneck to the gaff to be 5.25" to 4.5".
The plans also call for 2" mast rake in 10'.
Is the mast rake set by the angle between the partners? This mast has some checking at the glue joints also from sitting out a while. I am very close to deciding on a new mast.

[Ian McColgin]

People do all sorts of things, but the luff side of a mast should be straight with the taper on the sides and front.

Should you build a new mast, that taper can be put in while the chunk is still square as the eight-siding guide so often described on these screens (and we will again if needed) will follow it. If you build bird's mouth, the taper is put in in the staves.

But hopefully this is just a matter of an unfinished stick warping a bit.

Maybe. Now with all the clues, like the checking which tells us that you've a multi-piece stick, we have some cause to wonder about the grain allignment.

Take a good look at the glue lines to be sure that the individual bits run past your bow. If the do, carefully plane a c-hair off the heel of the mast (relieve the edges first so's you don't lift a splinter off the sides) to enable a good view of the grain orientation of each piece. Just a guess, but you might have a flat sawn stave on the inside of the bow.

Report what you find, maybe even a good photo, and perhaps someone smarter about wood warp - Bob, Dave, etc? - will have the answer.

G'luck

[ddeaton]

I will try and post a pic. I dont have my plane with me and the mast is here at my business.
This is a Wittholz cat and the plans lack a little for the gaff pole. From all I have read about Charles and this boat, he always leans towards the marconi rig. At least the first commissioned boat was marconi. I am going to call the fellow today I got the project from and ask about this.

[Mrleft8]

What's the dimension (diameter) of the mast where the bow is? If it's more than 5" I doubt that you'll get it to straighten out.

[Tom Lathrop]

The mast was never finished? That is a clue that the lower section might have been glued up crooked or that they tried to glue up some wood that was already bent and it remembered. It has happened before.

If that is the case, straightening it might not be the best thing to do. How about building out the off side with a taper and cutting away the other side. If you fear for the strength of the glue up, add some uni-directional glass around the splice. Many masts have been lengthened or scarfed after a break and lived long lives.

[Ian McColgin]

Brillian Tom. If the bow is concentrated at the partners, then a clothspin scarf to a new lower section would do quite nicely.

For cleaning off the endgrain absent a low angle plane, maybe the edge of a piece of glass or (this will hurt the blade only a little) a knife abused as a cabinet scraper.

[ddeaton]

The mast diameter at the partners is 5.25. The warp starts right above the transition as it starts to taper. The mast was finished, and varnished, but never stepped. Looks like it sat out a while, as one side has lost it's varnish and weathered grey. The glue joints are spread a little more than what I like also. My intentions were to strip, sand, and epoxy fill the splits, until I found the bend. I will post a pic.
Thanks

[ddeaton]

http://www.imagestation.com/album/pictures.html?id=2118787737&idx=10

[ddeaton]

http://www.imagestation.com/picture/sraid198/pea389f077c7cde59038512cb72d495b4/f0d6285d.jpg

[ddeaton]

http://www.imagestation.com/picture/sraid198/pea389f077c7cde59038512cb72d495b4/f0d6285d.jpg

[ddeaton]

http://www.imagestation.com/picture/sraid198/pf57bc474eac3547fd117db0ce322fdd2/f0d62940.jpg

[ddeaton]

http://www.imagestation.com/picture/sraid198/p6f87e6f4cbb040e2868afd0c38eaf374/f0d628cd.jpg http://www.imagestation.com/picture/sraid195/p1946a75d5477ca50d15578efa67b69a1/f14094e6.jpg
I am starting to figure this out!

[Railmeat]

Danny -
My guess is that the bend is due to storage. It was stored outside for a long time, as you have noted, and it is likely that it was stored unevenly. Dad glued it up out of multiple pieces, so I would doubt that one crooked piece would have pulled the others into a warp. It was once square and he planed it round, so I would think that any initial crookedness would have been faired at that time. Maybe not. You might be better off starting over nonetheless.

Don

[Mrleft8]

That pretty much looks like toast. I'm sure there are others here who could salvage it but...... I think building new, and using that as a flag pole is a good choice.....

[ddeaton]

I think you guys are right, It will make a nice flagpole. I am putting a lot of work in reviving her, I might as well not skimp on the mast.
Thanks for the help guys.

Don, did you turn your boat yet?

[Railmeat]

Danny -
The Penobscot remains unturned. I was off all this week (but the wife wasn't) and was hoping to get some more fairing done on the outside of the hull, but instead I played Mr. Mom. The wee one fills diapers and his stomach at a prodigious rate, and has little regard for my other interests. It's very unfair. For the first time ever, I'm looking forward to going back to work next week. At this rate, I'll be lucky to have her turned over by spring (just about the time you launch the catboat).

Don