Adding a genoa track (fixings)

[dave_gibsea]

Hi,

I am going to fit a new 1.2m Genoa track to take a new high aspect jib. Its going alongside the shroud bolts and I was intending using 5mm bolts and very large (ie 25mm) washers to take the load, the track is drilled every 100mm. The boat is a 26 ft Gib'sea 76 with foam sandwich deck, the biggest sail on the new track will be about 140 sq ft, My question is should I make up plates or will the large penny washers be sufficient?

Thanks,

Dave

 

[Scapa86]

I think the foam construction necessitates a backing pad, I’d be tempted to use a strip of any kind of hardwood and maybe even give the wood a coat of paint or epoxy before hand? What are you using to bed the track? I think butyl tape as hands down the best in this situation. Some really informative videos on you tube about bedding deck fittings with butyl tape

 

[geem]

I would buy some aluminium bar. 5mm thick as a continuous backing pad. Drill it to the same centres as the track and you have a continuous washer that will spread the load. To some extent the success will depend on how thick the glass is either side of the core. Make sure the aluminium is marine grade.
I have never had any success with butyl tape. In hot weather the stuff flows out when used as a gasket. We bed our deck fittings in Geocel Works.

 

[Poignard]

I think it would be best to sleeve the holes in the deck with thickened epoxy, otherwise you risk crushing the deck as you tighten up.

This WEST downloadable manual might give you some ideas (see pp 47-53):

https://www.westsystem.com/wp-content/uploads/Fiberglass-Manual-2015.pdf

 

[Boathook]

Really need to remove the core where the bolts will be to stop crushing. Picture is from the West manual, page 46 in my version

 

[Neeves]

It depends on the interior but I'd use a strip of stainless, rather than aluminium, but only for aesthetic reasons. I'd polish the stainless. If aesthetics don't matter then go for Geem's aluminium option. I added a Genoa track - but the reinforcing was built into the moulding - a strip of aluminium under ply wood all as part of the moulding. I simply drilled through to the aluminium and just through the aluminium and tapped the aluminium (which was 8mm). I used Duralac for the bolts/taps. My bolts were M8 but my headsail is 35^m2. I have had no issues. I don't recall the bolt spacings but 100mm sounds 'about' similar. The bolts matched the holes in the track. So if you are bolting right through - follow Geem's advise and pre drill to match the track, tap if you want, see later. Then drill and back fill with epoxy, as suggested, see previous posts. Then drill, again, through the hardened epoxy and the new holes will match the holes in the metal strip (stainless or aluminium). If you have tapped then bolt through and I'd add dome nuts to cover the bolt ends.

I also installed an extra winch, specifically for the tracks. They had the same original construction, ply and aluminium, so I installed the same way. I was not buying 2 winches and installed a turning block for the other track (but its a clear run between the turning block and only winch). This has the advantage that you control both sheets from one location (but I was saving money).

You would need to over drill and back fill with epoxy, as mentioned.

My track was slightly bent, or is slightly bent - but I don't think that relevant. The track came with little plastic washers, cone shaped, that fit into the holes in the track and separate the track from the stainless bolts. These conical washers must have a name - but I think you can buy them indpenendetly from chandlers (commonly red colour). You could tap the stainless strip, if you go that route, but you will still have exposed bolt ends, even if they are flush and I'd have them protrude and use dome nuts (aesthetics again). Polish the stainless before you instal.

I used Sika under the new track and on top of the gel coat. I also filled the holes with Sika, before installing each bolt. I tightened the whole lot down, cleaned up the Sika and then gave each bolt and extra half turn once it had set off.

None of this is difficult. It will help if when you assemble you have someone on the inside holding up the prepared metal strip but otherwise its a one person task and just needs a bit of patience (and good weather). I'd do all the drill, reaming out and epoxy in one day - allow the epoxy to set off - and the re-drill and instal the next day. If you tap the strip - that can be done at home in advance.

Just remember the Duralac!

Good luck

Take care, stay safe

Jonathan

If you go Geem's aluminium route you need the 5083 alloy which you should be able to source from any aluminium stockist. 5083 is the marine grade and used to make aluminium dinghies (and probably the tracks). The tracks might be anodised - don't recall - so don't sand them down or you will remove the anodising, which gives extra protection. For stainless you will want the 316 alloy (and it, a bar or strip of either, will produce a much more robust choice than penny washers - which will look naff on the interior.

 

[Iliade]

More than once I've snapped the 4 or 5mm bolts securing the track of my, admittedly large, genoa on my old quarter tonner. If the loads can do that to stainless bolts then the GRP needs all the support you care to give it.

(They were simple tensile failures, not corrosion or obvious fatigue.)

 

[scottie]

I would try the builders first as it may be that a backing plate already fitted.
When we fitted extra track on our Hanse because it was an option the backing plate was drilled and tapped and glassed in

 

[anoccasionalyachtsman]

I completely agree with re-coring the deck with epoxy in way of the holes, but I'd go for thick penny washers. Pre-drilling a strip would lead to tears if there's any curvature in the deck and drilling it in situ is a logistical headache, besides which it would have to be pretty meaty to offer and greater support than decent washers.