Suggestions for boom restoration

[troppo]

Been methodically working my way through my boat fixing stuff. Decided to take the boom off but not sure how to proceed. So, please check the pictures and tell me what you reckon.

In general I am thinking of taking everything off, cleaning corrosion off, putting back on with Tef-gel or Duralac between s/s and aluminium. But I'd like your thoughts.

Mast end: The s/s gooseneck fitting has been removed and can be used again. Underneath was white corrosion, pitted surfaces, ragged hole on each side from unknown, plus had several bolts missing.



Topping lift connection point: The end cap was quite corroded and the top bit is broken. On the two sides of the boom are dimples which I assume are part of a rod which goes through and secures the end cap on. Would I be right with this?



Clew outhaul: Only one bolt was holding it on and this one corroded so have not been able to remove it. I have pulled the track to the side to check under. On right there is pitting from corrosion. Two of the three other holes have broken bolts in them.



Fittings: This one has only two rivets on this side. Some rivets are not in properly. One fitting has a bolt going all the way through to hold the fitting on plus a few rivets.



So there you go, suggestions?

[forsailbyowner]

What a mess. Too bad your so far off. I have two booms that will probably end up in the scrapyard in much better shape. Imho it would be easier to find a salvage boom than to try to fix that one.

[troppo]

Haha, if I had your offer before I took the old boom apart, Forsailbyowner, I would have had a better chance of getting over to where you are : ). I sure ain't sailing anywhere at the moment. [Not that I could have got over there but I have no chance of going anywhere even around here apart from using the motor seeing as the boom is an important part of the system.]

troppo

[forsailbyowner]

I dont know what its like where your at but here it would be cheap and easy to find a replacement. I was given a complete rig. 40' mast boom. It sat on craigslist and didnt sell in 3 months for $200.I ended up cutting the mast up and selling it for scrap because It was getting in the way at a gals dock where it was sitting. A friend who does towing, repos, and salvage has a half a dozen sitting in his yard.

Ever thought of a wood spar? Gooseneck and hardware may work for something like that. On my next project boat the plans are to build wood spars. The woods used arent often expensive like pine and spruce.

[Jim Cate]

G'Day Troppo,

I would have to agree that replacement looks better than repair for that spar, for it has just too many faults. Booms are not particularly specific to a boat design. That is, you could use one from just about any boat of similar or slightly larger size. Thus, a few calls to riggers and such folks would very likely score a useable bit of aluminium, and at a reasonable price.

I'd start with any local sources, then start further afield... Bundy Port marina (can't think of the riggers name there),Scott Keogh in Manly, Allyacht Spars and Dave Lambourne in Hemmant, and so on. There are lots of abandoned booms around! You could even perhaps use a bit of mast section from a larger dinghy, and those too are commonly lying around gathering dust.

Good luck,

Jim

[Delancey]

I don't think you've gotten bad advice with regards to outright replacement but your situation doesn't look so bad to me and I might suggest you consider an approach that has worked for me in the past.

Basically, make a backing plate which you drill and tap for bolts to be placed inside the boom with the threaded ends sticking out. Threading the bolts into the backing plate stops them from turning when you tighten the nuts on the outside and also stops them from falling out, when you insert the backing plate into the boom.

In the case of the track or the goose neck you are looking at some type of bar or plate the length of your fitting or a little longer that you insert in the boom end with the threads sticking out, place the fittings on, then nut and washer.

Looks like for the outhaul you might have to cut the cap off the boom end which I don't think is a problem structure-wise the cap isn't really doing much.

It's possible your gooseneck fitting is a socket, as opposed to two halves that clamp on. You can actually tweak-out a blown-up latex glove to exert pressure on the bolts from inside the boom while you slide the socket over the end and align the holes. The glove will push the bolts out through the holes in the socket.

As far as the boom vang attachment, logic would suggest if two rivets per side has been sufficient so far, then four or six would be better. Keep them the same size as existing. Same goes for the track and gooseneck.

The point is that corrosion has enlarged the holes in the boom but you don't want to just put bigger fasteners in, where for example enlarging a hole comes at the expense of meat on another matting part. By incorporating a backing plate you are able to ameliorate the loss of material due to corrosion and keep your original fastener size.

Good luck!

PS, probably can find suitable sized aluminum bar stock at a builders supply, back by where they have threaded rid and angle iron. Plus bolts and a tap and the bar stock, maybe fifty bucks gets you sailing.

[troppo]

Thanks to suggestions here and from the Top Hat forum, I satisfactorily finished the repairs to my boom. It has been working well, and despite my tardiness with reporting back, I think it worthwhile to give this feedback.

I cut the end off the boom, the topping lift end, to (a) get inside the boom to remove the seized nut of the outhaul track and allow access for putting new nuts on and (b) clean up the end plug and reuse it. After cleaning the corrosion off the end plug and drilling out the corroded-in-place nut, I bolted on a piece of aluminium stock on which to attach the topping lift. Then I covered the mating surface with Tefgel and tapped it back on. The bolts were also coated with Tefgel.

[/URL]

The outhaul track I put green plastic tape along where it touched the aluminium and put in several bolts, coated with Tefgel, to replace the original one bolt.



At the gooseneck end, I covered the stainless steel touching surfaces with insulating plastic tape to hinder the galvanic corrosion.



Since I did not have the thick stock suggested by Delancey to cut a thread in, I tried what I had, thinner stuff, and it worked. What did not work was the double-sided foam tape. It was supposed to lightly hold the nuts in place while I carefully poked the stock into the boom and pushed the bolts through from the outside and gently caught the nuts on the first bit of thread on the bolt. Not sticky enough. At least it stops direct contact of stainless steel and aluminium so less galvanic corrosion. Awkward holding the nuts in place up the tube while I put the bolts through. Grrr! Got there eventually. Seemed very strong.





With the boom vang, I measured the size of holes in the boom and got stainless steel rivets which fitted. Some of the old rivets were too small and so were falling out. The new ones, coated with Tefgel, held securely.

It has been over a year since I finished the repair and have had no problems with the repairs neither have I seen any sign of the white corrosion, the galvanic corrosion, that was so obvious before. The finished boom is pretty. Pretty ugly. But it is working efficiently and is way stronger than what it was. Unlikely to fall off when I am out at sea. That will do me for now.

The story of the boom can also bee seen at: https://mildadventurer.wordpress.com...ring-the-boom/

cheers
troppo

[Jim Cate]

Troppo, nicely done! Shows what you can do w hen highly motivated. Glad that you can go sailing now, so enjoy t he summer.

Jim