This bit came off the other day? is it supposed to? 

Do I need to put some glue on it before I go out again or will some tape suffice?

Is the top 10 list of most important structural parts of the boat, that ranks about number three!! Tape will not suffice, and it most definately should not come off. 

This needs to be properly dried and epoxied back together.

If youn have ANY remote doubts about this contact a local boat repairer. It really is that important.

That's an image which will stay with me for a while... Where did the mast go when it came off?
Bigger washers next time!

Fortunately the mast-ram held it, The wood failed whilst pulling up the main so we were still on the pontoon.

how lucky are you!! easy fix ,normally it takes apiece of gunwhale or deck with it! IT MUST BE REALLY DRIED OUT FIRST.or you will only have problems later on.

Hi,

As well as a solid repair, it's going to be worth fixing a stainless steel plate underneath (drill holes as appropriate).
It may be necessary to form an inverted "U" shape so that the plate can be fixed to the hull as well...

With the static rig tensions > 400 lbs plus the load from the mainsheet I think you were lucky it happened near the shore...

Colin

If that wer my boat I would plug those bolt holes from the under side, dry it out (as phil says, really well), epoxy the pieces back together plug the holes from the top with as many plugs as it takes to reach the bottom ones. Leave for a couple of days to make sure it is set and re-drill the holes. You will be sure the the tension is in good, strong wood then and that the holes are all the way through not eating in from the bottom as does happen. They will also be exactly the right size for the bolts used as they tend to open up over the years a little. Should be fine then. Shame Blitz is a nice looking boat, but will be fine.

Hello

As all the others have suggested epoxy the section back using something like SP106 mixed with some microfibres and clamp into place, also work the thickened epoxy into the existing screw holes to create a solid plug. Once cured do as Colin suggestes, re-drill holes and fix s/steel back plate under deck with something like a steel webbing plate as the c/line of screw holes should be the same as deck swivel. 

If it has completely rotted then this is a different issue. You can inject neat epoxy into the rot as this will stiffen the rot believe it or not, otherwise woodwork skills may be required!

Richard

Dry the whole lot out and acetone (Boots sells in small bottles) the wood (yes) to remove the moisture debris and if you have a garage, heat with the boat inside for 24 hours (blocking up the door surroun and hang ablacket over the inside of the door to help keep the heat in) to make sure the joint is fully dried out. Over drill (both halves) the damage/pulled holes (suggest 7 mm min).
Then tape below the holes. Run epoxy and fibres into the holes and more runny epoxy over the bare surfaces of the two halves, G cramp (2) together lightly to hold in place (to tighly and you may distort(having taped around none damaged areas)).
Now wipe away the excess and make sure no residue on the varnish. if you do not have a heat lamp, rig a desk lamp over the area to cure the deck joint. Make sure it is not smoking or to hot that it damages the varnish (heat given off burns the back of your hand, to close), and leave till the following day. Then clean up and varnish top and bottom. Once cured, redrill the holes and either place bigger washers or better a small plate on the underside.
Do a good enough job and you'll find it hard to see the repair.
Best of luck.

Thanks for the tips, the acetone one is interesting, i shall try that.

Sadly there is a fair bit of rot, my plan is to cut out the rotten piece (probably about 1/4" of the 1" thick bridge piece) and laminate either a bit of mahogany or maybe ply back in.  The curved bit of pretty trim is also rather rotten .. I was thinking I might replace that too, looks like it might be maple/sycamore or maybe ash? very creamy white anyway. I doubt its Lime.

I'll put the top cap back in, and then drill oversize holes, fill them with epoxy and microballons, then drill the bolt holes through those, so the hole is through epoxy and not wood, should help when the water does run through.

Finally, I am minded to not use bolts, but use two U bolts, going right round the bridge piece, replacing the 3 hole plate/swivel on top with a 4 hole one made from a bit of 1.5mm stanless sheet.

Hopefully, that will do it.

Don't fill with micro ballons!  The stuff for strength are microfibres.  Microballoons are grand for fairing and are easily sanded.  Why? They don't have the strength of the fibres. The only danger I see of using acetone is that it is a great solvent for epoxy. Little known fact that if you have a piece of broken pottery glued with araldite then a good soak in acetone will soon soften it up and turn it gooey enough to allow a clean up and a proper reposition and glueing job.  Indeed a paper towel soaked in acetone makes an excellent wipe down for cleaning around an epoxied joint before it sets.  Before hand,  I would use a low wattage lamp below the damp area to dry it out although that shouldn't take too long if you are removing the rotten spongey timber which will be holding most of the water anyway. I would agree with the beefing up the area with a plate.   Hope this helps

Microballons is a no no as no strength. Wood would probably be Sycamore. Looking at the damage, try and replace with current part unless your woodwork is supreme as it could probably end up a real mess. If replacing, make sure your chisels and spek shave are razor sharp. Below the top the epoxy repair can be as large as need be to remove the wrot. So replace wrotten wood with epoxy/fibre and not ply as to soft and will crush.
Acetone is for the final preperation to make sure there is no foreign bodies on the surfaces, but make sure you allow all the Acetone to evaporate or the epoxy will turn to putty and not cure properly.

It's very important to consider the underside, and what will happen to the spinnaker when you pull it down.

There is nothing at all wrong with the debris, just that iut has failed. I'd be very suprised if it is rotten, but if it really is wet it can look like it's rotten. Once dry it may well be much harder, and certainly once soaked in resin it should be fine. I like the tip about using plugs, it would be even better in the hole could be tapered somehow from the bottom so that the load is pulling the repair together.

If it does turn out to be rotten i'd consult a boatbuilder.

I'd use exactly the same fittings that you had origionally. It's been fine on countless other boats.

I'm pretty sure its quite rotten, tapered plugs wouldnt work as the holes are drilled though the join between the bridge piece and the spinnaker chute lower piece. Any tapering woudl simply force the joint apart under load.

My woodwork is quite up to scarfing and laminating a bit of wood back in ... I shall try and get some Sycamore to replace that lighter piece as it has rotted away completely in a large patch, and is 90% detached anyway.

I'm beginning to like the idea of using U or J bolts right around the bridge piece a lot, puts the strain in the right places

Add a piece of stainless tube across the chute for the spinny to flow around without touching the wood. It will also add strength to the boat there. Plastic pipe will chafe through too easily just like the wood in your picture.

Don't listen to those above; a bit of duct tape will be fine ;-)

Looking again at your picture I think there must have been a significant crack through the bolt holes for a while allowing water in - there is blackening at the top of the picture.  There is a joint at the aft end of the piece which is not an ideal place structurally.  Doing something to beef it up underneath and spread the load sounds good as you are never quite going to regain the initial strength with epoxying what you have.  Whatever, just make sure that you get the spinny chute nice and smooth at the end as nothing makes better holes in spinnakers than edges of bolts