Deck maintenance part 2 (edges and heads of fastenings)

The experiences of Nick Ardley and F24 ‘Whimbrel’.

This article is for remedial action which can be taken with Finesse decks. If you have areas of irreparably damaged plywood, then a more drastic course of action will be needed.

See article on Deck Maintenance part 1 which was written by owner of F24, Gypsy, and posted December 2020.

There are several questions that come up from time to time about decks:

1. Damage to deck edges.

2. Rusting of fastening heads on decks and cabin tops.

3. Damage beneath stanchion/push pit/pulpit feet.

All defects, if dealt with, can assist in alleviating further problems down the years.

Ultimately, in time, all boats will probably require decks to be renewed to avoid a constant round of small repairs.

I have owned Whimbrel since her build in 1983/4 and her launch in the spring of 1984. I quickly cottoned on to any damage to deck sheathing due to sanding of cabin top beadings and upper face of rubbing band on the sheer strake. Damage to sheathing will eventually lead to water ingress into the plywood, especially with wicking up the end grain laminates.

All that know me will attest to my pains in pointing out about the care of deck edges when they become a Finesse owner.

As Whimbrel began to age, I also noticed signs of little rusting marks around the main decks, in the main. These indicators were a sign of the degradation of fastening heads. The fastenings are galvanised nails. Some have heads virtually on the surface of the ply deck structure. These appear to suffer most.

Note: I was told by ‘someone’ some years after having Whimbrel built that bronze fastening of decks was available as an optional extra. This is not supported in paperwork I hold, nor do I remember the class builder, Alan Platt, telling me so. I do not know of any boat so fastened. I would be interested to know of any.

I developed methods to deal with these problems early in my ownership of Whimbrel.

Occasionally I have had to carry out repairs to sheathing after lifting a pulpit/push pit foot for re-sealing or when renewing fastenings.

Repairs are best done during the dry months of summer unless boat can be covered or is stored in a shed. My preference is ‘high’ summer.

Epoxy: There are various epoxy kits on the market with differing hardening times. The choice is yours. With a 2-part epoxy, only enough needed to complete job need be mixed.

Deck Edges:

Plate 1: The sheathing can be thin

Look closely at plate 1 and you can see the markings beneath sheathing of the plywood laminate structure. Also, here, can be seen a definite line in sheathing as if ‘cut’ – it was in fact found to be very thin!

The deck coatings are cleaned back to the sheathing surface carefully with scraper and sanding paper over an area larger than the visible damage. See plate 2.

Make sure the deck coating/varnish corner to the rubbing strake is cleaned back to allow epoxy to have an overlap. Also, one does not want to ‘burst through’ the sheathing here – use care.

It is important at this stage to ensure the area remains dry and given time to ensure dry – a hot sunny day is great.

Plate 2 Don’t burst through the sheathing…

I have on occasions trickled some Captain Tolley’s Creeping Crack Cure into edge. The liquid is in fact a moisture curing compound.

In the third plate the area has been coated with a two-part epoxy. Note extent of area greater than first seemed. A deck fastening repair can be seen (brown filler). Two to three coats are often used, sanding between coats.

Plate 3 Two- part epoxy applied.

When cured, sand, coat with an undercoat primer a couple of times and finish with a couple coats of deck paint.

Masking the area can save further remedial action to varnish work…

Fastening Heads:

Plate 4 Tell-tale evidence of fastening head degradation

Note the little ‘speck’ of rusting (ferrous oxide) coming up through the sheathing and deck coatings in Plate 4. This is a clear indication that the fastening head has begun to degrade – this seems to be a head problem alone from hammering home damage to galvanising during build.

The following plates describe best the action I have developed aboard Whimbrel. The use of an anti-rust agent was a suggestion of a surveyor when I discussed this problem some years ago.

Plate 5. Area around fastening head with paint coating cleaned away. Sanding not shown.

Plate 6. Punch fastening down a few millimetres, no further than say 5 mm.

Plate 7. Drill the deck above fastening head to suit hard wood plug (teak). Various sizes are available. In the main, I use 6 & 8 mm plugs and occasionally 10 mm plugs.

Plate 8. Drilled deck ready for a plug.

Plate 9. Treat with anti-rust liquid. Follow instructions. In main, two coats dabbed onto fastening head sufficient. Allow to dry.

Actions at plates 10, 11 & 12 are completed in sequence in one go.

Plate 10. Plug glued and tapped home.

Plate 11. Plug cut back with a small chisel to below deck surface.

Plate 12. Coat area and top of plugged fastening with epoxy. I have often mixed a little fibre filler (brown) into the epoxy mix at this point.

One needs to work quickly…

Once the epoxy coating has cured it can be sanded and a further coat applied. Finally sanding area before then applying primer and deck coatings.

Sheathing/indentation repairs beneath deck fittings

On occasions when lifting a deck fitting, I have found a need to repair the area beneath. This can be the sheathing and or removing/levelling an indentation of the deck where fitting has been hardened down.

Deck indentation can be a problem with plywood decks. Aboard Whimbrel, I had this problem beneath rigging U-bolts, essentially from build. What I did will appear as a separate article.

A series of three plates and captions show repairs beneath the feet of a bow pulpit.

Plate 13. Deck sheathing was damaged when foot released. Area cleaned and ensured dry. One fastening was corroded and removed. Hole is plugged with a teak plug. Picture after a couple of coats epoxy and epoxy and filler and then sanded.

Plate 14. Plugged fastening hole drilled out. Prime/undercoats applied.

Plate 15. Foot (different one) bedded onto a marine sealant and refastened.

General Note:

Of course, I accept that other owners may have more to add to all of this or have a different approach, that is expected.

This entry was posted in Uncategorized. Bookmark the permalink.

2 Responses to Deck maintenance part 2 (edges and heads of fastenings)

  1. Hugh Brading says:

    The 2 articles regarding deck repairs I can full agree with . I had to lift all the deck fittings on Liberty as most leaked. fortunately the plywood beneath had not suffered. however I covered Liberty completely with a big industrial tarp and let the wood really dry out. I then used Ronseals wood hardener on all the holes just to be certain there was no softness. I only used A4 stainless fastenings from a reputable supplier to ensure no “rusting” would take place. I never encountered any rust marks on the decks. Perhaps if one asked Alan prior to the build he would use bronze. Certainly other yards in Essex used bronze. The poor quality of the fibre glass sheaving material must be evident on nearly all the F24s . Certainly Liberty and Pippit both suffered with cracked sheaving just above the rubbing strake. As Nick says dry the wood thoroughly then epoxy if the plywood hasnt suffered. I was lucky with both boats. And once everything was sealed I never experienced leaks into the interiors. Now as an owner of a GRP boat let me tell you that they suffer from leaks too. Many as brass screws were used to fix most of the deck fittings such as handrails etc. Also in quite a few early GRP boats the head lining was in sections. The joints were covered with hard wood battens. These were held up by brass screws which were screwed up into the deck head. Over the years the minute piercings through the gel coat allowed the brass to corrode. I took me several weeks of very hard work to strip the head linings off remove all traces of the screws and seal all the holes. I then employed an upholsterer who specialises in refurbishing Rolls Royces to fit a new headlining which did not require holding up with battens. Result has been a nice dry cabin with virtually no mould appearing anywhere.

  2. Nick Ardley says:

    Pieter, I can see where the covering of deck edge has been ‘cut’ into by sanding of the shear strake. Treat as described if ply is good. Let epoxy also coat edge of shear strake.
    Gypsy’s owner described edge repairing, epoxying after.

    Underside of decks/cabin tops – looks like a rub back/strip and recoat needed.

    Stanchions – I re-bedded mine down onto a sealant many years ago. Think originally they were just bolted down. The middle hole in fitting could have a screw fitted. I found the sealant blocks it up.

Leave a Reply