Installing deck hardware question.

[Roger Peterson]

Well, after almost 5 years, I'm almost ready to install the deck. My question is... What's the best way to attach the deck hardware?

I was going to lay the plywood decking on the framing and mark the frame outlines and hardware backer locations and finish the underside of the decking with an epoxy coating and then paint. Do you "BOLT" thru the decking and backer plate or "SCREW" the hardware in place.

Do you use 3M 5200 for bedding or polysulphide? Do you drill and pour an epoxy bushing for each of the fasteners?

I'm also wondering, do you use the same method for the rest of the hardware IE:blocks,fairleads cleats ect.

Thanks,

Roger

[Peter HK]

I've always bolted through if possible (and I think it is by far the better way), though a long screw into a lot of wood might work in some cases. Remember that if the fitting is only putting shear stresses on screws, or if the stresses involved are very small, they will work OK.

I usually just drill the holes a little bigger than the bolt and seal them with epoxy- pipe cleaners are a good tool for this- rather than making a formal epoxy and filler bushing.

I've used sikaflex mostly for bedding. I understand 3M 5200 is hard to remove if you ever want to in the future. In theory plastic (say, screw-in inspection ports) is best bedded with glazing silicone as it doesn't react and cause cracking of the plastic in time.

I'm about to start decking too- Cs17 #165.

Peter HK

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[Roger Peterson]

Thanks, Peter,

It looks like we are at just about the same place in construction.

Any hints or suggestions on how to best locate the deck hardware?

Are there any "Rules of thumb" for cletes or fairleads?

Roger

[Doug Cameron]

Think about where the lines are going to go.  For instance, the main halyard fairlead should be set so that it leads the line clear (fair) of the hatch (remember to allow for the cover and don't just measure to the opening), and the main halyard block should either be on a pivot or the pad eye set so as to turn the line from the mast above to the fairlead without the line impinging on the cheeks.

On my CS 20, I fly a mizzen staysail, so the cleats serve a dual purpose as docking connections and an attachment for the staysail tack (18" aft of the mast on center).  I then used cleats with a hone in the center to finish the trick.

Put the parts down on the deck, move them about them they are right., mark the spots, then have a cup of coffee (or, tea for you Graham!), sit down and cogitate a while, then make any corrections that occur.  This is wood, after all, so you can patch and fill mistakes, especially if you are going to paint it.

[Roger Peterson]

Thanks Doug,

Sounds like a plan to me...

I just stocked up on Guiness...

I think I'll wait on the Guiness until AFTER I drill the holes. ;D

Roger

[bruegf]

Don't ever use 5200 unless you are absolutely sure you will never have to remove whatever you are bedding with it.  I've ripped gelcoat right off the fiberglass trying to remove a pedestal that some idiot bedded with 5200.  Made a real mess of my cockpit sole.

Fred

[Hirilonde]

Don't ever use 5200 unless you are absolutely sure you will never have to remove whatever you are bedding with it.  I've ripped gelcoat right off the fiberglass trying to remove a pedestal that some idiot bedded with 5200.  Made a real mess of my cockpit sole.

Fred

Amen

The Jamestown Distributors catalog has a chart showing the tensile strengths of the 3M and Sika lines of adhesives and beddings.  I can't find this chart on-line.  I do remember a few of the stats as I use the products.  3M 5200 = 700 psi, 3M 5200 fast cure = 600 psi, 3M 101 = 139 psi, and Sikaflex 291-LOT = 250 psi.  The numbers themselves probably mean little to most of us (myself included).  Being very familiar with Sikaflex 291-LOT though, having used it and removed stuff bedded in it, the numbers give me a fair relative comparison between products.  I find Sikaflex 291-LOT to be the best all round bedding adhesive.  It has enough adhesive hold to assist in mechanical fastening, cleans easily, the white stays white and with a little care you can get stuff apart later.  Because it is a polyurethane and not a polysulfide like Lifecaulk or 3M 101 it can be used safely with plastics (ex. polycarbonate ports lights and PVC inspection ports).  The only real down sides to it is that it comes only in cartridges, and not small tubes, and it has a shelf life, which shortens drastically once opened.