repairing cracks at stantion post base ?

T

tsekul

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Ok the boats out and lining up jobs for the winter.

I am looking at two stantion posts that are next to each other one has radiating cracks and I can see slight movement (spongy) at the base when I apply pressure at the top. the other is an old repair done badly. The toerail is aly with machine screws and nuts attaching it to the deck.

The question is should I go anywhere near this, I assume I would have to lift the toerail to do a proper repair. My boat is a GK29 circ 1979.

I am a little concerned about water ingress into the core, and was going to redo the nonslip paint on the deck over the winter so was thinking of giving it a go. Any thoughts from the more enlightened out there.

The other issue is as its on the hard outside getting a dry enough period to get it done could be an issue.
 
tsekul

What's a " GK29 circ 1979"?. What is it made of? What sort of deck is the the stanchion mounted on?

Cheers
 
I don't know the GK29 specifically, although I'm sure someone will be along who does. However, the likelihood is that the toe-rail fasteners also secure the hull-to-deck joint, in which case it's rare for that part of the deck to be cored. Indeed, being double thickness, it's one of the stronger parts of the boat.
Can you remove a fastener or two to investigate?

The readiating cracks you mention could simply be in the gel-coat; but equally the sponginess you mention is suggestive of possible water penetration. Wet GRP can go like that whether cored or not.
 
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How are the stanchion bases fixed to the deck/toe rail? A feeling of sponginess can result from a loose bolt/screw on top of a layer of sealant; the stanchion wobbles a little on the sealant bed, giving a spongy feel. May be nothing more than loose fixings on a sealant bed. Cracks probably no more than surface crazing on the gel coat......

However, it could be a disintegrating balsa core. Only way to tell is to remove the fittings, peer into the resulting hole to see if GRP all the way through or if it the core giving up the ghost. If it is a rotting balsa, others will be along soon to tell you how to deal with it. If its solid GRP, all you need do is check that the cracks don't extend below the gel coat, tidy the surface up and re-bed the fitting using a thin layer of sealant.
 
Stanchions should never be bolted onto balsa core. The balsa should be removed and a ply insert should take the crushing effect of the stanchion bolts.

If there is rotting balsa there it will have to be cut out and replaced with a ply insert. On my yacht I have overly thick ply inserts which are about 1/4 inch (5mm) above the level of the deck. The idea is to stop rainwater and water running down the deck from seeping down the boltholes.
 
My experience of cracks and putting off repairs is that you are likely to make the situation worse. For example, I removed a flue from my Rival and patched the hole temporarily. This resulted in water ingress and eventually a larger repair had to be carried out as the balsa needed to be cut back further to obtain sound balsa. Now my decks are 10 mm GRP at this point so there was no flex but on a thinner GRP this would have been an issue. So, this is very much a case of 'a stitch in time saves nine', don't put this off is my advice.

Repair methods are very well explained in West's repair guides: -

http://www.westsystem.com/ss/use-guides/

Note that the repair guides, although promoting West's products are suitable for other manufacturers products as well.
 
tsekul said:
I am looking at two stantion posts that are next to each other one has radiating cracks and I can see slight movement (spongy) at the base when I apply pressure at the top. the other is an old repair done badly. The toerail is aly with machine screws and nuts attaching it to the deck.
Click to expand...

You are none too clear with what the exact problem is. Is it damage to the stanchion bases themselves, if so new bases need to be fitted. If it is damage to the grp, then action will need to be taken. The radial cracks will be from a heavy impact on the stanchion causing massive leverage on the grp. The deck will be balsa cored, but should be a plywood pad under each stanchion. The slight spongyness is suggesting water ingress and some rot has started in the plywood pad.

The repair will be slightly messy depending on exactly how far the plywood has suffered. You will need to remove the stanchion base. This will involve some work inside as Westerly are well known for fiberglassing over the nut and bolt studs of deck fittings. A Dremel type cutter will remove this material easily to get at the nut. Once the bolt has been removed then check with a small screwdriver if the core plywood has gone soft. If it has then there are choices as how to best repair this. The worst case is you will need to cut a section of deck away and replace the plywood and then lay up a new deck section. Hopefully that will not be necessary. Take a small alum key and insert the long side into an electric drill and spin this in the hole to remove the rotting ply from each hole. Then seal the underside and then fill with an epoxy thickened with fibreglass strands. Seal the deck with some gel coat and fair in. Then drill new holes to fix the bases back. You can use this method over fairly large areas if you drill further holes. As you intend to repaint the deck, this would make sense. The two attached links explain both methods.
http://www.westsystem.com/ss/bonding-hardware/ Check out the bonding studs as it is a variation on this principle.
http://www.westsystem.com/19/pdf/Ew19_Replacing_core.pdf

Hope this helps.
 
Thanks guy's for the responses.

The stantion bases are cast aly with three countersunk attachment points two are attached to the aly toe rail directly. one is screwed into the grp deck. This is how all the stantions are fitted, except the one that has had previous repaired damage. This one has a different base with just two fasteners that attach directly to the aly toe rail. The repaired section where the old station base was obviously stripped out of the deck and has been filled poorly the smoothness of the repair is bad. What makes me want to do something about it is that the cracks around the two posts are black indicating water ingress ?

These are the only two with an issue. I am hoping I can repair without lifting the toe rail. Or is that going to be another bodge up ?
T
 
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From memory the GK29 has through-bolted sockets for the stanchions.
If, as you suggest the actual tube-socket has cracked, you need to replace them. My replacements came from the Bursledon Barge.
If it's crazing of the upper gelcoat/grp the problem could be considerably more serious.
As has been said, you should never put any fitting onto a composite surface without considerable re-inforcement. The added disadvantage of end-grain balsa construction is that any water that finds its way in will cause delamination and probable breakdown of the balsa core.
One attempted botch is to drill holes around the crack and inject liquid epoxy - but the only way to be sure is to take off one side and rebuild using either ply or Corex.
There are enough sad stories of Bowman through hull fittings to last a lifetime.
 
tsekul said:
I am hoping I can repair without lifting the toe rail. Or is that going to be another bodge up ?
Click to expand...

Not all GK29s have an alloy toerail; many just have wood. The hull/deck join is covered by the wooden rubbing strake, so the toerail isn't "structural" as it is in some boats. I'd have thought you could remove the 2 stanchion bases and investigate what's under them without disturbing the toerail. However, if you do need to take it off, it'll probably be a horrible job because you may need to remove interior liners, etc.
 
I have a balsa cored deck. Brilliant until you get water ingress.

If you have a floppy stanchion fitted straight to a cored deck the obvious thing is to add strength to probably top and bottom to give a good foundation to the stanchion base and to the underside of the core.

I thoroughly recommend looking at tufnol whale for the pad both on top and below. https://www.google.co.uk/search?sit...4.0....0...1c.1.58.hp..4.3.1273.0.uDOYJoHMjJI

No water ingress can ruin it and depending on thickness will not bend. Can be machined, glued to, filed, will not rot.... I know it's pricey and dense therefore heavy, but I'm not sure why it's not used more often...... any ideas?

Cutting out the sodden core if there is any is either as/West or why not use a rod of tufnol again, epoxied into an enlarged hole and sealed in?
imho much easier and extremely strong and I reckon more reliable long term.

I did cut out some dampness on my deck when fitting 5 new, slightly larger hatches. All that mixing and filling etc... what a job! But a great result!

S.
 
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