Mount Pads

[mbd]

There was a thread going around on the Triton List recently about mounting the deck hardware on pads to raise the mount point (and water intrusion point) above the deck level and any standing water on the deck:


I have mounted numerous additions to Head over Heels on mount pads....not the stanchions or pulpits(!), but just about everything else.
I feel that sharp inside corners are places where dirt can accumulate, so I made pads, some as thick as 2 inches for anchor rollers, to raise attachments off the deck. The bases are teak, cut and contoured to match the part I was attaching.
Each base was designed to extend about a half an inch from the base of the piece I was attaching. I route the upper edge for a smooth round over. I would then remove the nonskid a half an inch out from that. The pads were saturated with epoxy and let to cure. I used epoxy with filler to glue the teak in place. When cured, I would use epoxy and sandable filler to run a fillet around the deck/pad joint to create a smooth transition from the horizontal to the vertical. I usually use a West System stir stick for the radius of the fillet, but in larger fillets... Each pad was then painted, white in my case.
The result is a pad which has a smooth, rounded transition from the deck to the top of the pad. The appliance I attached was then centered and through bolted for a clean and hopefully "factory-like" finish.
Here are the pictures Rob Squire sent out. Thanks Rob!

Anyone else done this? As I'm gearing up for my recore, this is something I'm certainly going to consider! Simple and elegant - great idea!

[CapnK]

Personally, instead of painting the blocks, I'd go ahead and glass them in, perhaps with pigment. (...Or maybe not - might use polyester resin (for UV resistance) in a clear glossy finish to show off that teak. :)) Seems like painting those blocks would just cause more work down the road, though, when they need repainting in a year or so.

Good idea, though, and good pics of the implementation. I like using the router set shallow to remove the non-skid - very clever. Thx for the post, Mike. :)

[mbd]

I was thinking once Tony G. perfects his molding techniques and lets us all know how to do it, that making solid blocks would be the way to go. That way there's nothing to rot. Or even building up the area with foam core material and glassing it in and sanding it.

Would that work?

[mbd]

With the arrival of the stern rail and after cutting out some more deck with rotted core underneath where the stanchions had been mounted, I've been thinking about this topic again.

How about a plaster or clay or even playdough mold? The stanchion bases or other hardware could be pressed into the material to make an exact match, let the mold harden (or not), then epoxy with thickener and/or high density filler could be poured into it and let it set. You'd only need the final product to be 3/8" or so. I'd make it thicker initially so it could be sanded to fit the camber of the deck, etc., then epoxied in place once it was fit.

What would/could/should I use as a mold release in this scenario?

[ebb]

Commadore Bill uses fat varnished teak pads on some of Maitai's fittings.
Not sure why you have to have an impression of the stanchion foot in a pad to which it will be mounted? My first caution on this is that saltwater shouldn't have an opportunity to soak the base. Even if you put the rail on with rubber. Water will puddle anywhere. Especially in little cracks.

If we are talking about mounting hardware on composite:
Believe the foredeck should be recored befor mounting hardware, and the stanchion base mounted on rubber gasket with a backing plate inside. But you could holesaw a round hole just thru the TOP skin of the deck into questionable balsa where the pulpit bases mount and dig it out. The holesaw is an easy way to get a decent shape. If you are close to the toerail, it's not all balsa. Then fill the hole in flush with the deck with epoxy/mat. Could even glue back on the piece of deck you made with the saw.

This will get the pulpit mounted and later you can do the bigdeal deck recore. Inside, I would glue on a larger backing plate than the hole you've filled.
There's no balsa core in the aft deck, ofcourse, and putting in backing plates will be a real chore. Might have to hire a little people to get in there.

It is interesting idea to beef up the mounting area of a fitting with an exterior pad, but I believe you still have to have a backup pad inside to spread the load over the skin. The cabin top is a real problem with its floating interior liner.

Disassembling 338 produced a collection of fiberglass squares that Pearson used as backing for track and stanchions, etc. Backing is essential to mount anything anywhere on the decks. Hope I understood yor concern? :confused:

[commanderpete]

Maybe you dont want to make a very rigid mounting for the pulpits.

I've bumped my bow pulpit into a piling and seen the deck flex beneath it. Something has to give. Bending and kinking the pulpit would be bad.

If the worst should happen, the bigger the backing plate, the bigger the hole ripped in your deck

I wonder

This is Commander 105 after being attacked by another boat during Hurricane Isabel

http://www.pearsonariel.org/discussion/attachment.php?attachmentid=1691

[mbd]

Ouch! Strange, it looks like the fiberglass showing on the ripped deck in the picture has not even been wetted out??

On the mount pads: my goal is to move the "seam" where the hardware is attached to the deck to a level higher than the normal deck level. i.e. If the fitting where at a low spot, the water would pool around the base of the mount pad rather than the seam where the piece of hardware is attached to the deck. (Now I need to hunt around for a picture to show this - I think Cape Dory decks are made with this feature...)

[ebb]

Mike, this is fundamental stuff.
Hope Mike Goodwin comes in on this.

105's damage is extensive. It looks like it was caused by more than a bump or a single attack. It looks like it took some time to cause it - a lot of banging and pulling and pushing.

The old polyester laminate in 338, as an example, is amazing hard and strong. It is possible, like with tabbing as an example, to 'peel' it back with a sharp chisel. This has happenened on 338 a couple times. It is most disconcerting to suddenly get bare fiberglass out of what looks like 'saturated' translucent green. The peeling stops and doesn't seem to continue - it seems to be an example of what happens to frp in SHEAR. Or, what to call it: sideways stress. I think frp can be prone to this, tho I've never run across this in words, nor trained as an engineer.

This maybe is what we're seeing in C'pete's photo. It took a lot of work for Isabel to do that, and it took time, doncherthink? We're looking at huge force being applied to the EDGES of the deck and hull, once the joint was breached by the piling.

I'm for wider backing plates every time. It is in the nature of fiberglass skin construction. I'm for the tube to bend befor a hole is pushed into the deck. A hole from a stanchion being ripped out? THAT is hard to take! I believe I would want the deck, whatever, beefy enough so THAT wouldn't be possible! I would want the tube to break befor it caused a hole thru the deck.

Flatter (rather than taller) and wider backing plates with chamfered edges is the way to go imco. And creating a sandwich with a top plate coupled with the inside one - nothing wrong with that.

But no hard edges, if you do it to 'code'. A hard edge creates a break point, like maybe a crease in a sheet of paper. Kinda gives the deck or hull an idea of where it can break. All transitions smooth and gradual is the theme with fiberglass.

[bill@ariel231]

MBD - "On the mount pads: my goal is to move the "seam" where the hardware is attached to the deck to a level higher than the normal deck level. i.e. ... I think Cape Dory decks are made with this feature...)"


Mike you are correct, I replicated CD's feature on my stern rail install by wrapping the stern rail bases in a release fabric (e.g. saran-wrap) and bedding the stern rail in place (temporarily) in thickend epoxy (a 1/16th to 1/18th inch lift from the deck was all it took). once the epoxy was hard, a little sculpting with a dremel tool was all it tool to finish the pad.

[mbd]

You wouldn't happen to have any pictures of the process and/or finished product, would you? ;)

Maybe it would clarify what I'm evidently not explaining very clearly...

[bill@ariel231]

I can post an "in-progress" picture tonight. I took some close up pictures of the process after the rails were bolted in place but before painting that will make this clearer...

[Al Lorman]

A number of people do believe that raising deck intrusions is a good way to prevent leaks. I've been watching, via the Internet, as a very skilled guy rebuilds a C&C 38. He used premade fiberglass sheet stcok to raise things like his deck fill. Here's the link to his diesel deck fill raiser: http://www.wbryant.com/StellaBoat/Projects/deck/diesel/index.htm
He made a similar pad for his steering pedestal.


Al Lorman

[bill@ariel231]

Mike

I bedded my stanchion bases in thickened epoxy to make up for the small mismatch between the deck and the stanchion bases. It also picked the bases up 1/8th of an inch (like the Cape Dory 33 etc.). no leaks 10 years later. Here's the method I used: (1) the stanchion was wrapped in plastic wrap to protect it from the epoxy goo; (2) a thickend epoxy circle was troweled on deck where the stanchion base was to meet the deck; (3) the stanchion was bedded in the epoxy (all 6 legs at once); (4) once the stanchion pad had hardened, the pad was trimed with a dremel fitted with a small sanding drum. Of cource, the final install needs a backing plate below decks. here's is a drawing:

[bill@ariel231]

here's what the stanchion bases looked like before the paint:

[bill@ariel231]

I couldn't resist. while the epoxy was out, I took the liberty of changing the handles on the cockpit lockers...(off topic but you may have a bucket of epoxy mixed up for the bases)...

[mbd]

Thanks Al. Nice site. I've been wondering about prefab plastic sheets not only for the pads, but also for backing plates. I'll have to look into that a bit more. Though, I must say I prefer Admin Bill's functional and decorative teak backings for the cabin. (I'd still like to know how he mounted the handrails opposite each other - one outside and one inside)

And yep! That's what I'm talking about Bill. Though, I was thinking I'd make a mold, then sand down the the piece and glue it in place. But, your way is more straightforward. Nice results too.

2 questions: 1. Do I need high densitiy filler? I'll be recoring under the mast too, methinks. and 2. Did you reuse your deck skins on your recore, of glass and new skin on top? OK, 3. What did you use for core material?

PS. I didn't even consider trying to mount the stern rail on the taff rail. Nice and out of the wet deck area, but how on earth did you back those? Must've just used washers?

[bill@ariel231]

Mike

a couple of answers in no particular order.... Much like your side deck recore, both the top and bottom skin was reused on A-231. On the my foredeck, I recored from below saving the outer skin. the whole deck was finish off with two layers of 6 oz cloth. Under the mast step... the original balsa core failed. I've replaced it with solid mat & cloth.

As for thickeners.. I've used West 406 for almost everything except fairing.

core material... forgive me, I confess A-231 is using 1/4in ply on the decks & balsa in the coach room (I've grown to like divinycell after using it on a friends boat).

backing plates... 1/8th inch stainless for the side decks, fender washers for the bow & stern rails.

cheers,
Bill

[mbd]

On the my foredeck, I recored from below saving the outer skin.Why from below? To save the shape of the foredeck? I was thinking I may do one "panel" at a time on the foredeck for the same reason. Still not sure how extensive that portion of the recore will be.

Have you got any more pics of your mount pads? You can send 'em off-line if no one else wants to see them... :D

[bill@ariel231]

recoring from below wasn't entirely my choice. A-231's foredeck was in pretty bad shape after the work of previous owners. the deck had delaminated to the extent that a previous owner tried to "fill the core" with spray foam insulation and reseal the deck with tile grout. the result was a deck swollen to 6 inches deep in a couple of spots. only the upper skin retained any hint of the original dimensions. If you have the option of recoring from above that is always preferable.

I don't have any other pictures of the backing plates on file. I'll see what I can do about that..

[mbd]

:eek: Thank Neptune for my PO's! Holy smokes what a mess... Periwinkle is one lucky little boat to have found you.

Not pics of the backing plates - your mount pads and your process.

Have you had trouble witht the stainless plates corroding or rusting or anything? (Is that a stupid question?) :o

[bill@ariel231]

no problem with the Stainless backing plates (they still show a mirror finish).

sorry, I don't have other in-progress pictures of the installation of stanchions and rails.

[mbd]

Here we go: stanchion repair (http://tritonclass.org/mir/99%20stanchion%20repair.html) (From the Triton Association Maintenance page (http://tritonclass.org/mir/))

[c_amos]

FWIW,

I used a salvaged piece of deck skin to make the raised pad I am mounting the bit on.

The rise is only about 3/8" but I like the idea of getting the mount up off of the deck.... I wish I had saved the skin from the starboard side... :rolleyes:

I will try to remember to bring the camera to the marina and take a picture.

[mbd]

Craig, you've gotta post some pics, man! You're killing me over here. Recore, mount pads, new anchors,etc. ... Yowza!

FRP has been recommended for this purpose and backing plates when I remount the hardware. Anyone know a good source?

[CapnK]

Mike -

We used to lay up solid slabs - maybe 4' x 18" x 3/8" - to make surfboard fin blanks. If it comes to it and that is your only or best option, it is fairly simply to do: Get a piece of glass plenty larger than your eventual slab. Cut *a bunch* of pieces of glass cloth, and inch or two bigger than you'd like your final slab to be. Laminate them to the glass, 2-3 pieces at a time, all at once. Use plenty of resin; what you squeegee out of your laminations can be squeegee'd right back in the bucket and used to wet the next pieces, and so on. Once it cures it'll lift right off the glass, and be of a fairly uniform thickness.

A few tips:

Get a nice thick rubber squeegee, the kind you can buy at a auto-body supply store. They sell it by the inch or foot. Get extra - you can custom make a few sizes of squeegee for future projects with any excess. :)

Kick your resin (polyester) medium-slow, because the thickness of the slab will generate heat when it starts curing, accelerating the process. Too much catalyst and it'll burn, so be conservative if anything. If you can get some UV-activating catalyst, that would be great - pick a sunny day, lay it up in the garage, once it's nice and ready, open the garage door. :)

You can use a run of the mill polyester resin from a hardware store, nothing fancy or expensive needed.

I'm with you - pics, Craig, pics! :D

[c_amos]

Most of the pictures I took last night did not come out very well.....

Kinda like my progress laying on my back with my head in the anchor locker... messing with fairing the backing plate for the roller. :mad:

Here a picture of the bow, you can kind of see the mount pad on the bit;

http://sailfar.net/gallery/albums/userpics/10014/BowRoller1.jpg

[mbd]

Kurt, that sounds like it would do the trick. Unfortunately, time is not my friend these days, or rather, I have very little extra so I'll probably go the "quick" route and buy something... :o

Craig, very nice! Looks great! 3/8" looks just about right. Nice clean looking foredeck, did you recore it? Hmmm, no bow pulpit? I'd like to get a mooring bit too. How big is yours? How do you like it? Where'd you get it?

[c_amos]

Hmmm, no bow pulpit?.....?

The deck was recored, and the bow pulpit is sitting in my dingy right now.... :rolleyes:

I feel like I am making NO progress as of late.

[mbd]

Are you planning mount pads for the stanchion and pulpit bases as well? Given the stresses regularly imposed on them, I would think those are the most crucial locations for raising their attachment points above the normal water level on the deck with mount pads... If/when you do, feel free to regale us with plenty 'o pics of your process! :D

[c_amos]

I made up mounting pads for the stern pulpit from fiberglass

I did not have any more used deck skins to recycle, or the fancy stuff form McCallister-car so I just laid up some layers and used a hole saw to get the 3" cicrles I wanted;

http://sailfar.net/gallery/albums/userpics/10014/Backingplate%7E0.jpg

THese were bedded in thickened epoxy. I used my gloved finger to radius the edges and sanded them once they dried.

http://sailfar.net/gallery/albums/userpics/10014/Smollet_Pulpitpad2.jpg

The finished product not only helps keep the water from collecting around the mount, but actually works as a kind of external backing plate to help distribute compressive force applied to the pulpit.

[mbd]

Nice work!