Page 1 of 1

Cracked bow fitting weld

Posted: Sun Feb 21, 2016 5:46 pm
by JohnBrand
Sula's bow fitting is a twin-roller setup with the forestay connected to the vertical steel plate between the rollers. Late last season I noticed a crack about 3cm long at the front of the weld holding the vertical plate to the horizontal base. The front of the vertical plate has pulled up by about a millimetre.

The 10mm bolt which forms the axle of the bow rollers passes through all three of the vertical plates (centre and two cheek plates) mounted on the horizontal base, so it looks very unlikely that the forestay plate could actually move any further. Nevertheless, of course I would like to have the cracked weld repaired. However, my local welder has told me that it will be impossible to re-weld with the bow fitting in place because the heat would, at best, damage the glass fibre deck below the fitting. There is in fact an airgap of about 2mm between the bow fitting and the deck but this apparently is not sufficient.

Taking the whole fitting off will be a horrendous job. It is held on by 4 bolts on top, through the deck, and a further three on a s/s strap down the bow. All of the corresponding nuts are heavily glassed in. The only possible access is through the hatch into the chain locker, and from there I can't even reach the nuts.

Has anyone had a similar problem, and been able to solve it without deconstructing the boat?

Grateful for any advice...

John

Re: Cracked bow fitting weld

Posted: Sun Feb 21, 2016 11:09 pm
by mikebuggy
I had exactly the same on my Oceanranger. No problem to take the bow fitting off. I took mine off with the mast still up. The welding was done locally and fairly economically. I had all three uprights re-done. I also had a triangle made of heavy thick alloy to match the bolt holes and placed inside underneath the deck. In my view ALL boats should have chainplate and rigging attachment bolts and nuts refitted at 'mid life' anyway. It also gives you a chance to use a better quality stainless replacements than the originals as well.
You need to be a bit creative getting the fastenings off inside, as they are beyond arms reach. Experiment with taping or jubilee clipping attachments (grinders, drills, ring spanners, sockets, etc) to extensions like broom handles or alloy poles etc. For winding off nuts once loosened, or for the initial spinning on of nuts, I use a length of rubber orange gas hose with a socket driver shaft fitted in one end and a suitable socket. Treat each fastening as a mini project. You can actually just get head, one shoulder, and one full arm in. If grinding wear a mask as there is no vent. You need to flood the place with light as well. Mini grinding attachments, hole saws with shortened centres, dremels etc have all been used. On these jobs I often just use a hammer and chisel on the GRP around each nut, but avoid blunting the chisel on the nuts. It's surprising how easy the GRP 'cap' comes off. Just take your time and do the project a bit at a time. I have plenty of photos of when I did it. Do let me know if you need any further advice. MB 07867805595

Re: Cracked bow fitting weld

Posted: Thu Feb 25, 2016 10:30 am
by JohnBrand
Thanks very much for this, Mike - it's encouraging to know that someone else has solved the problems! I was at the boat yesterday and had another look - as you say it looks doable with tools on a stick, and some contortionist's tricks. The socket fitting at the end of a bit of gas pipe is a brilliant idea. It looks as though I'll need to remove the windlass motor and cables before I start on the main issue.

I guess it's necessary to remove the curved piece of stainless steel around the bow at rubbing-strake level as well - another half dozen nuts to unearth! But maybe loosening that will be sufficient to slide out the piece of the fitting that runs down the bow.

I'll be away for 6 weeks or so from late March - so I think this particular project may be for when I get back. I'll post again when it's done, and maybe get in touch with you if I run into particular problems which you might have overcome.

All the best,

John