metal mast repair

Wow Donna! You must be in some serious racing! I hate it when you call "Starboard!" and they don't respond...

Well, looking at your pictures, which are very well done and really help to answer your question, it looks like you have an Abbott mast (as opposed to a Proctor mast). I will tell you how I managed to repair my Proctor mast, and then I will make suggestions for your case. The good news is, if you decide to follow a similar course of action, the weld zone will be stronger than the original material so the end result is not a compromise, instead it becomes an exercise to achieve a final result that is as invisible as possible, which is very possible. I should also mention that, here in Seattle, we have probably the best welders in the world, no exaggeration, most are certified by Boeing over the years and experts of aluminum aircraft repair.

My experience:
My Proctor mast sheared into two pieces just above the goose neck fitting a few years ago and I managed the repair for about $75.00 and a weekends worth of work. In my case the shear was perfectly horizontal so, after removing all the fittings (spreaders, halyards, anything that was not riveted and anything that was plastic and within about 3 ft of the future weld zone which gets hot,

I built a large plywood and 2x4 fixture that fit onto my table saw and would slide like a table saw fence, then I used a carbide saw to "dress" the mast to a nice smooth flat and horizontal surface. that shortened the mast by about 3/16ths of an inch (I was very lucky to get away with so little).

Of course both pieces had to be dressed. Then using a hand file I put a heavy chamfer on both pieces, the chamfer started within about .02 inches of the inside wall. Chamfering was easy (with a good file) and took about 20 minutes. When the two butt ends were put together and, aligned, a deep "V" was formed allowing the weld to penetrate all the way to the inside of the wall which is key to restoring strength.

The next step was to build a fixture used to hold the two mast pieces in a straight line, allow them to be clamped so they do not move and give plenty of room (clearance) around the weld zone so that a welder can do his/her magic. I will send you a photo of my solution but the idea was to deliver the mast all ready to weld so that the welder does not have to invest any time in setup and can go straight to work on welding. This meant I was charged $50.00 instead of hundreds.

As for welding, almost every weld shop can handle aluminum but this is "thin wall" project and unless you find a shop with a light duty, thin wall welder, you risk a botched job because normal welders will burn right through the thin material. I found a welder near Fisherman's Terminal (Ballard Bridge area) who had an industrial TIG welder specifically designed for thin wall. This fellow had 40 years of experience and he filled the "V" with a beautiful bead of weld that was extended above the outside wall of the mast so that it could be filed flush.

After the bead was filed flush I used some industrial scotch bright to polish the weld zone so that you could not see where the weld took place. After a couple of years this bright finish will oxidize and match the rest of the mast. In the meantime I put a decal over the zone.

Suggestion for your mast:
The dents need to be removed because the mast will have no strength where bends exist. I am suggesting that you cut the mast twice so that all of the bend and dent zone exists on the middle pieces, which from your picture looks to be about 1 foot long. I would then take this 1 short piece to an auto body shop and ask them to use a mandrel and dolly to force the dents out and a hydraulic press to straighten it by eye aided with a straight edge (which they will probably have). Once this is done, follow my experience as noted above. When you cut your mast it is very important to cut it normal (90 degrees) to the "good" part of the mast so that you do not shorten the mast more than necessary. With two cuts and care you might only lose 3/8th of an inch, which is nothing. You will have to raise the sail that much higher. Notice I never made mention of a sleeve. A sleeve adds weight and frankly, with a decent alignment fixture, it is not required. Furthermore, fitting a sleeve will take just about as much time as building the fixture and then you will be stuck with a sleeve inside the mast causing problems for your halyards. Remember a penetrated weld is stronger than the original material.

Help if you need it:
I will fix your mast for you (pro bono) if you pay for the materials and welder's time. Of course there would be no guarantees but I would do the best job I can. Or you are welcome to stop by and use my table saw (I have a monster), we could chop the mast together, then you could manage the job from there...

Roger

From: Al Schonborn [mailto:uncle-al3854@cogeco.ca]
Sent: Sunday, October 19, 2008 10:40 AM
To: Youle-White, Roger; Donna Barton (W7978)

Hi, Roger:

Have begun the Fall Weekly Whiffles with a vengeance and thus been reminded that I had intended to post your fine article on mast welding not only in the WW (next week 27 Oct.) but also in the WIT - see http://www.wayfarer-international.org/WIT/WITindex2.html where it now sits at http://www.wayfarer-international.org/WIT/maint.repair.ref/mast.repair/mast.repair.html. I have raided the Picasa album you referred us to but am missing (I think) the pic of your "solution" (ref. "The next step was to build a fixture used to hold the two mast pieces in a straight line, allow them to be clamped so they do not move and give plenty of room (clearance) around the weld zone so that a welder can do his/her magic. I will send you a photo of my solution"). If there is one can you point it out or send it? I'll appreciate your input to confirm that I have put your pics into the right places?

Will get to the trailer write-up and the Okanagan report soon - I promise! Am really snowed under right now!! (not literally, thank goodness!!)

Best regards,

Uncle Al (W3854)

----- Original Message -----

From: Youle-White, Roger

To: Al Schonborn

Sent: Monday, October 20, 2008 3:58 PM

Hi Al, it appears I have miss-filed the photo's showing the alignment/weld fixture. I have over 30,000 digital pictures, and all are in well defined file folders but it's still a manual process. Also it is possible I became "involved" in the welding process and forgot to take pictures at that stage (I do that sometimes). Frankly at this point (about 5 or 6 years later) I don't remember if I took a pic or not. I will look again this week but if I can't find it here is a text description.

"The purpose of the fixture is to save weld-shop time (money!) that would otherwise be used to aligning the mast, assuming the shop has the resources to align a 20 ft object in such a way that gives access to the weld zone. Building a fixture ahead of time takes the pressure off, allowing you make sure the quality is built in. The requirements of the fixture are 3 fold; (1) To align the two segments of the mast; (2) To allow easy access around the weld zone big enough for a husky welder with gloved hands, arms, chest, to easily lay down a bead of weld without obstructions, getting his/her clothing caught, etc.; (3) the fixture must have sufficient rigidity that it can be transported to the weld sight without affecting the accuracy of it's purpose . I suppose a 4th requirement, the one that always gets us into trouble , is, to achieve all this as cost effectively as possible.

The fixture looks a little bit like hopeless box kit. Cut two sheets 4x8 sheet of 0.75 MDS into eight 12 inch x 8ft strips. MDS is fairly dimensionally stable, but it's not very rigid so by making two boxes held appart by 2x4's (like a box kite) the end result is reasonably rigid. Start by placing two strips on a semi-flat floor end to end, with a 2ft gap making a 18ft span. The gap is where the mast welding takes place. Attach the two panels with two 16ft 2x4 and use glue to make a very strong union. Assuming you did all this on the garage floor, call this the horizontal assembly. Now Attach 2 more 6 inch panels to form two vertical surfaces. Screw into the same 2x4's as used for the horz panels. You now have a "C" shaped assembly that has a degree of rigidity and will have more when you close the "box" with the last two remaining panels, but not yet. Put the two pieces of mast inside the "C" and center the weld zone in the middle of the 2 ft gap. Push the mast so that it is centered between the two "structural 2x4" (not toughing them) and hold the mast pieces in place with some small cheek blocks that you screw into the horz panel. Stretch a .020 wire along the length of the 18ft fixture, raised up so it is not touching anything and stretch it straight but not so tight as to distort the fixture. Set the wire up about 1 inches to the left of the mast. This wire is the "reference straight line". Now carfeully move the cheek block until the mast is aligned with the wire both in horizontal and vertical planes. This may seem difficult but with a bit of fenece you should be able to accomplish this in 15 or 20 miutes, the key to success is buiding some cheek block ahead of time and making sure they are big enough to support the mast so it does not rotate. Use pan head screws so the cheek blocks do not split and pre-drilled them. Focus on getting 4 cheek blocks per mast section set so that the mast section is aliged with the mast, then then add 10 or more blocks per mast section to really secure it for transport. The cheek blocks will not stop the mast from lifting up and out so drill some holes into the panel and using rope, tie the mast to the horz assembly thereby keeping the it firmly in the clultches of the cheek blocks. Now attach the last two panels to convert the "C" to a 4 sided box. A 12 inch square box is surprisingly rigid but for transport, screw a 3rd (or even 4th) 8ft 2x4 accross the "gap" for added stiffness. As the welder works, he/she can rotate the box on any of the 4 sides to gain good access to the weld zone that is only interuped by the 2x4's located in the corners of the box (away from the mast. The 3rd (and 4th) 2x4's can be removed prior to welding (if more access is needed). Only use a welder that has professional high quality light duty (for thin applications) mig welder. Mig welding is very hot which reduces the size of the heat-affected zone."

I'll draw up a sketch tonight...

Roger

P.S. Just visiting the link you provided, everything looks in order, except the missing picture.... This is a tremendous resource, just keeps getting better and better.

----- Original Message -----

From: Al Schonborn

To: Youle-White, Roger

Sent: Tuesday, October 21, 2008 11:39 AM

Hi again, Roger:

I must confess that these latest instructions boggle my mind completely. It's an area where my ignorance is monumental. So I'll just post it as is and give people the chance to put it to good use. Will add the promised sketch if you have time to produce it!!

Also look forward to the whole story of the Okanagan Rally that appears to be imminent!!

How's the hockey these days???

Best regards,

Uncle Al (W3854)