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Old 01-05-2016, 22:19   #1
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Rebedding formerly glassed bolts - Help !

You ever have one of those projects where everyone who "helped" along the way should have known what to do before tumbling down the rabbit hole and leaving the problem for you to solve? There are these four bolts that hold the U bolt plate that attaches to the compression rod to keep my mast from pulling up on the deck. Well, they have been sheared from the bolts that seem to have been fiberglassed into my keel step (hope the picture explains this better). What is the best way to fix this? Should I try to fill epoxy in the existing holes and tap for larger bolts, or drill new holes in that spot? You can see that one of those bolts is also broken off and still in the hole, so I might not have many options. This is a Freedom boat so there aren't stays holding the mast down. There is a collar around the mast that bolts through the deck and a threaded rod that goes through the base of the mast to keep it from twisting on the step, but that's it. I would think this compression rod is probably an important piece to keep the deck from flexing and so it needs to have a really strong attachment. There is no access underneath. Has anyone dealt with something like this and can help me out here?
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Old 01-05-2016, 23:47   #2
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Re: Rebedding formerly glassed bolts - Help !

Maybe use an epoxy with chopped glass strand for added strength?
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Old 02-05-2016, 00:17   #3
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Re: Rebedding formerly glassed bolts - Help !

But then I read this:

Threads cut by sheet-metal screws into fiberglass lack the strength, consistency, and durability that machined threads inside a metal nut or other thick metal component can provide. Bolts or machine screws must be used to secure any component or piece of hardware essential to boat function and/or safety that might experience a load that will or could pull or pry it from the boat.
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Old 02-05-2016, 01:08   #4
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Re: Rebedding formerly glassed bolts - Help !

I would think there is a threaded backing plate embedded in the fiberglass. Threads in fiberglass don't hold unless epoxied in place. I think, looking down the holes, you'll see a plate or nuts of some kind. If you have to drill out the broken screw, you'll need special hardened bits.
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Old 02-05-2016, 01:38   #5
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Re: Rebedding formerly glassed bolts - Help !

Threads in g10 hold better, if that's an option. Maybe glass/bolt in a larger diameter plate of g10 on top of the original? Or grind sheared bolt flush and redrill holes in different positions? Vague ideas here from a dark corner of the internet.

Also, the forks on the end of the compression rod t-fitting look pretty twisted to my eye..?
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Old 02-05-2016, 03:13   #6
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Re: Rebedding formerly glassed bolts - Help !

I have a bunch of questions, which impact what solution to pursue. But consider this one.

A 4" wide, inverted stainless "T" section, with 5mm - 6mm bolts on either side of the web, set in a staggered (zig zag) pattern on each side. With these bolts being 1" to 1.5" apart, longitudinally, along the base of the web. And you would bond them into the step itself.

Thus your load would be spread out over a huge footprint. There would be no highly loaded fasteners in the new tang/chainplate. Nor would there be, anywhere in the step, where the relatively small fasteners would be bonded in place.
Ergo, no point loads.


That said: It would help immensely to know more about the; materials, hardware, & loads involved. As to me, the first big question, is finding out more about what the mast step is made out of, & it's strengths & weaknesses.
So as to be able to decide what the options are regarding what can be attached to it & how. And to begin to ascertain this, a good first step might be to remove some of the finish on it.

So, is there any indication as to the make of the padeye, so that we can look up it's rated SWL?
What's the diameter of it's bail, thickness of it's base, overall diameter, bail height, & diameter of it's fasteners?

What diameter is the tie rod? And I'm assuming that it's not true rod rigging, based on what appears to be a threaded nut on it's lower end.

How is the tie rod attached to the underside of the deck/the hardware topsides? And what are the spec's of the attachment hardware on it's upper end.
The more detail on this, the better. Much like with the padeye on the lower end.

Plus, pics of; where it attaches, to what, & how, would really help as well.

Any ideas as to the makeup of the mast step/pad? Especially to include thoughts or composition data which would indicate whether drilling more holes into it, for more fasteners would compromise it's structural integrity.

I ask these things, the last question especially, as it'd surely be nice to be able to both bolt & laminate in place, a big/several pieces of G10, to which a new padeye(s) could be properly affixed.

And, given the ideas on the table, it would make sense to find out what kinds of loads that the bolts for the current padeye could sustain, if they're simply epoxy bonded in place. Not that that would be anywhere near my first choice.

Also, there's nothing which says that the tie rod needs to be affixed to the step via the one round padeye. One option might be to connect it to multiple, interlinked padeyes. Or to fabricate a much bigger plate/tang, such as one in the shape of an inverted "T". Which would have multiple fasteners bonded into the base of the step.

Plus, you needn't stick with the original tie rod. It could be replaced with Dynux Dux, or wire. With it's lower terminus attached to many load bearing connecions, as denoted above.
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Old 02-05-2016, 05:19   #7
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Re: Rebedding formerly glassed bolts - Help !

Uh Oh Gamster... Looks like we're stuck in the slip... No good for a sailing junkie...

Maybe not what others would do, but for me... 2 fixes, 1 super quick, 1 not too hard...

1. If your rod will allow it, rotate the plate 90 degrees, drill new holes and tap... I'm not a fan of flathead phillips in this tension load... If it were me, I'd utilize some flat washers and some fasteners with a real head...

2. Grind and prep the surface, sandwich a 1/4 stainless plate between some biax, and drill and tap as above... lemme know if you want a diagram if it's not clear...

And Unciv has a lot of good things in there above...
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Old 02-05-2016, 06:17   #8
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Re: Rebedding formerly glassed bolts - Help !

Quote:
Originally Posted by HappyMdRSailor View Post
....
1. If your rod will allow it, rotate the plate 90 degrees, drill new holes and tap... I'm not a fan of flathead phillips in this tension load... If it were me, I'd utilize some flat washers and some fasteners with a real head...
....
This would be the easiest, but I think Happy means rotate 45 degrees, not 90.

I would suspect that there is an aluminium or stainless plate glassed in there.
Fill up the old holes with epoxy or caulking to avoid corrosion.

If it is an aluminium plate with stainless machine screws threaded in they will eventually fuse together with corrosion unless you coat the threads with something like teff gel.

Cheers,
JM.
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Old 02-05-2016, 06:50   #9
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Re: Rebedding formerly glassed bolts - Help !

On the design concept (below), I forgot to mention that the inverted "T"-plate (Tang) would be 12"-18" long. Basically the full length or width) of the mast step. So as to Really spread things out in terms of loading. And to give you a Massive surface area, into which to bond it's fasteners.

Plus, to take things one step further. Said Tang could also be mounted atop a piece of G10 plate that would be both; bonded, & heavily tabbed to the step. With the Tang's "glued in" mounting bolts running all of the way through the G10 plate, down into the step itself.
And with the fastener's bonding holes, also assisting in securing the G10 plate to the step proper. So that the entire unit would be a monocoque structure.

Thus, I'm thinking that you'd likely "get by" with such construction. And that with the addition of the plate, plus it's tabbing. The step would probably be fine from a structural standpoint. Meaning that it'd probably be more than strong enough to handle the described fastener pattern.

Also, in case it's not clear below, in the quoted post. When I'm referring to using bolts to attach the Tang, in a zig-zag pattern. My meaning is that there would be a zig-zag pattern of bolts on both sides of the Tang's vertical web.
Thus, if the Tang is 18" long, & the bolts are spread out at 1.5" intervals, you've got 10-11 bolts per side. So that in reality, 5mm bolts should be plenty strong enough.

And on this design idea, I'm definitely open to constructive criticism. As, yeah, designing this fix from just one picture is a "challenge". For there's no substitute for a real, hands on, eyes on, inspection. So as to truly get a feel for things.

Quote:
Originally Posted by UNCIVILIZED View Post
I have a bunch of questions, which impact what solution to pursue. But consider this one.

A 4" wide, inverted stainless "T" section, with 5mm - 6mm bolts on either side of the web, set in a staggered (zig zag) pattern on each side. With these bolts being 1" to 1.5" apart, longitudinally, along the base of the web. And you would bond them into the step itself.

Thus your load would be spread out over a huge footprint. There would be no highly loaded fasteners in the new tang/chainplate. Nor would there be, anywhere in the step, where the relatively small fasteners would be bonded in place.
Ergo, no point loads.


That said: It would help immensely to know more about the; materials, hardware, & loads involved. As to me, the first big question, is finding out more about what the mast step is made out of, & it's strengths & weaknesses.
So as to be able to decide what the options are regarding what can be attached to it & how. And to begin to ascertain this, a good first step might be to remove some of the finish on it.

So, is there any indication as to the make of the padeye, so that we can look up it's rated SWL?
What's the diameter of it's bail, thickness of it's base, overall diameter, bail height, & diameter of it's fasteners?

What diameter is the tie rod? And I'm assuming that it's not true rod rigging, based on what appears to be a threaded nut on it's lower end.

How is the tie rod attached to the underside of the deck/the hardware topsides? And what are the spec's of the attachment hardware on it's upper end.
The more detail on this, the better. Much like with the padeye on the lower end.

Plus, pics of; where it attaches, to what, & how, would really help as well.

Any ideas as to the makeup of the mast step/pad? Especially to include thoughts or composition data which would indicate whether drilling more holes into it, for more fasteners would compromise it's structural integrity.

I ask these things, the last question especially, as it'd surely be nice to be able to both bolt & laminate in place, a big/several pieces of G10, to which a new padeye(s) could be properly affixed.

And, given the ideas on the table, it would make sense to find out what kinds of loads that the bolts for the current padeye could sustain, if they're simply epoxy bonded in place. Not that that would be anywhere near my first choice.

Also, there's nothing which says that the tie rod needs to be affixed to the step via the one round padeye. One option might be to connect it to multiple, interlinked padeyes. Or to fabricate a much bigger plate/tang, such as one in the shape of an inverted "T". Which would have multiple fasteners bonded into the base of the step.

Plus, you needn't stick with the original tie rod. It could be replaced with Dynux Dux, or wire. With it's lower terminus attached to many load bearing connecions, as denoted above.
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Old 02-05-2016, 10:56   #10
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Re: Rebedding formerly glassed bolts - Help !

Bite the bullet and get a yard to fix this professionally. The plate needs to be removed, rebuilt, and reinstalled. The holes probably best to be redrilled(removing the bolt ends, rethreading, etc). Glues and other glop stuff will not hold. This type of repair is not for amateurs.

If I am not mistaken your boat has a cored hull. Balsa most likely. Good luck.
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Old 02-05-2016, 11:33   #11
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Re: Rebedding formerly glassed bolts - Help !

Hi gamayun~~~ Looking into the holes would probably not let you see if there is a plate below the glass. Drill a small hole in the center of the raised area and pay attention to the filings...drill slow. if you are able to drill the length of the original screws and find no metal shavings there is no backing plate. if on the other hand there is metal filings...with the sheared screw I'd think there was...., then re-drill the holes in the plate and deck for larger bolts.... I'd go with hex-head bolts....and tap the glass and plate below. A course thread would be ester to tap

If there is no plate I'd mortice out the glass and glass a backing plate in about a 1/4 or 6mm below the surface. the surrounding surface not the raised one. position the pad eye and re-drill and thread/ tap. I'd make the plate as wide as i could fwd and aft up to an inch on either side and at least an inch on either side port and stbd. in your mortice slant the vertical sides to be wider and the bottom than the top of the hole. this will add strength to the glass, when pulling vertically.

trace the plate. drill a bunch of holes to depth, in area to be removed and chisel it out. Keep a sharpening stone handy to re-sharpen the chisel as needed. the glass will dull it fast. find a cheap chisel or one that is already rusting.

I forget what they call that rod, to stop the pumping of the cabin top. but back the adjusting nut off a little to insure yu don't place the pad eye too high and can't tighten the rod enough. You can always shim the pad higher but not lower it. shimming the other end up top would just make it too high and get in the way of the boot.


Hope this helps. Good luck.
Lance
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Old 02-05-2016, 13:18   #12
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Re: Rebedding formerly glassed bolts - Help !

Quote:
Originally Posted by tinkrman69 View Post
...I forget what they call that rod, to stop the pumping of the cabin top....
Panting rod.
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Old 02-05-2016, 16:56   #13
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Re: Rebedding formerly glassed bolts - Help !

Quote:
Originally Posted by gamayun View Post
the rabbit hole and leaving the problem for you to solve? There are these four bolts that hold the U bolt plate that attaches to the compression rod to keep my mast from pulling up on the deck. Well, they have been sheared from the bolts that seem to have been fiberglassed into my keel step (hope the picture explains this better). What is the best way to fix this? so I might not have many options. This is a Freedom boat so there aren't stays holding the mast down. There is a collar around the mast that bolts through the deck and a threaded rod that goes through the base of the mast to keep it from twisting on the step, but that's it. I would think this compression rod is probably an important piece to keep the deck from flexing and so it needs to have a really strong attachment. There is no access underneath. Has anyone dealt with something like this and can help me out here?
On the last hole, the empty one, can you see down the hole? For the others, the bolts are probably stainless and over time the bolts seize in the nut or plate if it is stainless. The key thing is that when you reassemble this make sure you coat it with a grease or silicone. Now for the broken one you need to heat it up. If you can grab it with vise grips... good. Heat the end of the bolts with a soldering iron for a few minutes and then try to unscrew the bolt with the vise grips. If it does not come out... get a welder to come over and install a washer over the broken bolt and then a nut. Then weld the bolts through the nut and the nut will become welded to the bolt and the washer will protect you fiberglass. Cool down the nut with a wet rag while trying with a wrench and back and forth try to free up the bolt. For the invisible one you might have to drill it out and rethread the hole. There is probably a plate that has been fiber glassed in place for that fitting. Grease the treads but seal the fitting to prevent water seepage.
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Old 02-05-2016, 17:35   #14
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Re: Rebedding formerly glassed bolts - Help !

Answering Some questions might help you to decide what to do here:

Why was this removed ?
Was it Broken ?
Did it pull out ?

If it pulled out, perhaps it needs to be stronger/re-designed.

But, If you just tried to remove it and broke/stripped fasteners, then the design is probably sound and you can put it back by either:

1/ removing the broken fastener, then drilling and tapping new larger holes.

or

2/ rotate the fitting 45 deg. and drill and tap new holes for new fasteners (same as old).

If you don't feel comfortable with drilling and taping, find someone who is, or who can teach you.

Cheers,
JM.
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Old 02-05-2016, 19:02   #15
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Re: Rebedding formerly glassed bolts - Help !

Thanks terra nova. for some reason I thought it started with an F
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