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Old 03-05-2016, 05:18   #16
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Re: Rebedding formerly glassed bolts - Help !

Quote:
Originally Posted by NahanniV View Post
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.
HAHA!!!

NOOOOOOOOOOOOOOOO..... I really meant 315 degrees silly!
(good catch jm)

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Originally Posted by tinkrman69 View Post
Thanks terra nova. for some reason I thought it started with an F
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Old 05-05-2016, 18:04   #17
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Re: Rebedding formerly glassed bolts - Help !

These were all really great suggestions and ideas to help me with the next (baby) steps. Figuring out how something was constructed on a boat can be so maddening at times! It took a couple of days to get back to this, and then another day of head scratching until the light bulb finally went off. This is what I think is going on:

Scraping away the gel coat from one of the holes seems to reveal a round piece of G10 that has been fiberglassed into that step. It sits a bit proud from the base (see original picture), which makes sense to me now. Some of the threads are still usuable where the four bolts were tapped into this, which would not have been possible in fibgerglass. I also drilled a small hole in the middle to a depth that was as long as the bolts were to where they seem to have been sheared off from the nuts. The bit seems to connect with something hard down there that might be under a metal plate perhaps about a 1/2 inch under the fiberglass layer. I really don't want to drill any deeper into my bow because there was one time I screwed through to the gel coat on the upper side deck. I would like to never repeat that where the boat meets the water...

So. I am leaning toward bedding a much larger piece of G-10 to the step and perhaps using multiple inverted T's to attach the panting rod (thanks for that word, Terra Nova!). What do you all think of this? I would remove that round piece of G-10, which will likely shed some light further as I go along, but this is the idea for now. Is it better to bed G-10 to bare fiberglass or keep the gel coat intact as much as possible? Seems the glossy surface would be a stronger attachment for the bonding adhesive.

As far as getting some yard guy to do this work, if I knew they were putting in the same thought and care that I would into figuring out a solution, then I might consider it, but it's a crap shoot, right? It was actually the yard guys that pulled my mast that caused the problem in the first place. I had gotten everything off the mast (sails, boom, vang, collar bolts, etc. and by myself, too) except I couldn't figure out how to get the horizontal threaded rod that runs through the base of the mast without stripping the threads (now I know to use two nuts). The yard had forgotten about my appointment to remove the mast and had sent their usual riggers home. The people they sent were as clueless as I (really, why didn't they know about using two nuts?). They got so far as removing two of the glassed-in bolts to the panting rod, before deciding the other two bolts were not going to come out, so they crushed the threaded rod with channel grips and removed it from the side it was supposed to go out from. I wasn't watching all this because I had assumed (ahem) that they kinda would know what to do. It's a boat yard, right? (Never mind, don't answer that one!)
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Old 05-05-2016, 21:19   #18
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Re: Rebedding formerly glassed bolts - Help !

What I would suggest is to measure the depth of the hole you drilled carefully.
Like this:



Compare that to the length of the fasteners. I re-read, but I am not sure if any of the fasteners came out without breaking ?

If the fasteners are longer than your test hole, then I think you have a metal plate fibreglassed into your mast step. If you were not easily able to drill it, it may be made of stainless.

The threads you see in the fibreglass are not necessarily meant to hold anything, they just get cut when tapping into the metal plate below.

Here is an image of something similar to what I think you have:


The picture you posted shows what looks like a very well constructed mast step. It has worked for many years. No need to re-invent it, just fix it.

Cheers,
JM.
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Old 05-05-2016, 21:21   #19
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Re: Rebedding formerly glassed bolts - Help !

Well when you take up the old disk...yes you might find that there is a metal plate below. You say all the bolts seem to have sheared off? if so there should be at least another 1/4 inch down there. It's not likely a bolt would shear at the bottom of a threaded synthetic hole, at the top yes. I understand your fear of drilling too far ;-) been there, done that. but if it's harder than the glass you drilled through to get there it's not the outer layer of the GRP hull. Yes stepping through it and investigating as you go is a good practice. So keep lookin'.

bonding to the gelcoat won't be very strong. bonding to a smooth perfectly flat surface, like a glass pane, would be strong. but that surface is uneven. abraiding it with, say a 24 grit grinding disk would be sufficient. Taking it down "just" to the glass.

Polyester to polyester, has somewhat of a chemical bond but the majority of the bond is mechanical. Epoxi is strictly a mechanical bond. Meaning it grips the surface. Abraiding the the surface will give it more to attach to. Think of the little hairs on a Geko's paws. hell, little hairs of glass are what's holding that plastic together, you're floating in,ay?

Oh, and make sure you clean the bonding surface real good.
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Old 05-05-2016, 22:18   #20
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Re: Rebedding formerly glassed bolts - Help !

Hmm, what I'm hearing you two say is to start digging into it, figure out how it was constructed, then redo it the way it was done. Everything on this boat has been well constructed so I don't doubt it was done right the first time.

The depth of the test hole I drilled is 1.3" the bolts and the hole depths where they came out of are 1". None of the fasteners had come out without breaking. Looking back on the bit, I think it bottomed out on the drill (doh!) and it wasn't resistance after all, and then I stopped not wanting to go further.

This input is truly helping me. Hope you can keep giving me suggestions. It's like I'm uncovering a clue, little by little, to a puzzle that should be simple, but is inordinately complicated.
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Old 06-05-2016, 06:18   #21
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Re: Rebedding formerly glassed bolts - Help !

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Originally Posted by gamayun View Post
Hmm, what I'm hearing you two say is to start digging into it, figure out how it was constructed, then redo it the way it was done. Everything on this boat has been well constructed so I don't doubt it was done right the first time.

The depth of the test hole I drilled is 1.3" the bolts and the hole depths where they came out of are 1". None of the fasteners had come out without breaking. Looking back on the bit, I think it bottomed out on the drill (doh!) and it wasn't resistance after all, and then I stopped not wanting to go further.

This input is truly helping me. Hope you can keep giving me suggestions. It's like I'm uncovering a clue, little by little, to a puzzle that should be simple, but is inordinately complicated.
Not exactly what I am saying; Don't dig too much or you will need to do a lot of unnecessary work to get it back to it's original strength.

To clarify: is the broken part of the bolts 1" long ?

When you drilled the test hole did you see any metal come out ?
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Old 06-05-2016, 06:21   #22
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Re: Rebedding formerly glassed bolts - Help !

TOTALLY LOVE the drawing JM!

Gam...

Drill a little further in your center test hole with a slightly smaller bit... wrap a bit of tape on your bit so you know your depth without bottoming on the chuck... See if you can get some metal shavings to come up... Guessing construction is as JM drew... No further construction would be required... just rotate drill and tap...
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Old 06-05-2016, 11:07   #23
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Re: Rebedding formerly glassed bolts - Help !

As you say "all the bolts were sheared" and they sheared one inch down. then there should be a plate. But then again, I looked up the freedom 38 and it appears to have a free standing mast. If that is the case with your boat, then I'm not sure why you have a panting rod. On keel stepped masts with standing rigging, it is put in to limit the rising of the cabin/deck at the mast caused by the pull of the shrouds at the outer limits of the deck. they are not only pulled up by the mast but in towards the centerline, causing the deck to flex upwards.

I guess it could be there for panting caused by the main sheet and maybe a staysi'l. In that case I guess they might not have deemed it need to be as strongly mounted.

Of course, not knowing for sure would keep me looking. there is a lot of force on the mast step, both vertically and horizontally. So things should be pretty thick at that point. I would try another 0.2 inch's or drill out one of the old bolts. I still find it hard to believe a bolt can sear 1" down in a threaded synthetic hole. with metal at the bottom and corrosion, yes it would shear at or near the plate. If the threads were only in a synthetic medium then it would shear at or near the top.

It's your call. If you choose to thread it into, just the glass or G10. keep an eye on it. if it pulls loose it would more than likely, just pull the bolts out of the holes and let you know you need to go further to a plate. if you do notice panting, shorten sail and address the problem at the next stop, as it could necessitate repairs else where, if left too long.

are you sure there were no metal filing in the test hole? did you drill it slow, as in slow rpms, so they don't go flying around?
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Old 06-05-2016, 12:02   #24
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Re: Rebedding formerly glassed bolts - Help !

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...
I guess it could be there for panting caused by the main sheet and maybe a staysi'l. In that case I guess they might not have deemed it need to be as strongly mounted.
...
Yes, every line not cleated on the mast, but led back to the cockpit puts an upward force on the deck when tensioned.

I don't think it is as much as the force from a rig with shrouds.
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Old 06-05-2016, 12:05   #25
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Re: Rebedding formerly glassed bolts - Help !

Gamayun~ if you decide to drill out the old bolts. I'm thinking they're 1/4 inch bolts. that being a 1/4" drill bit will be slightly bigger that the threaded hole...good...with a !/4" bit drill down..making sure to stay perpendicular, let the hole guide you...with slow speed and just enough pressure to cut, till you get to the bolt. add more pressure and rpms till you've made a dimple in the top of the bolt. this will find the center of the bolt. using a center punch, find the center of the dimple and give it a good whack with a 16 oz or so hammer...making sure the punch is straight. then with, say a 3/64" bit, find that center mark and drill. you'll only need about 300 rpms...about half throttle on a variable speed drill motor going faster will only heat things up too much and dull the bit...drill in as much as you can up to 1/4" depth, as the bit is only so long. switch to the next size bigger bit 1/8" or 5/64". with just enough pressure to keep contact drill to the bottom of the pilot hole. be carful as the bit will catch easily, with too much pressure and or speed it will break. you don't want that!! once at the bottom of the pilot hole gradually add pressure and speed and drill down another 1/8" or so. at this point you need to look to see if you are still centered. using the 1/4" bit go back in and drill just till you are cutting. pull it out and look down to see the bevel and notice if it is even. if not with a 3/16" bit angle it to the side with the narrowest bevel. with low rpm and pressure when it starts cutting gradually raise it to perpendicular and drill through. at this point you can try an easyout, a type of screw extractor. incert it in the hole and tap it lightly with a hammer then holding downward pressure turn it with a wrench counter clockwise. if the screw still wont come out then drill it with the 1/4" bit. and retap with a 5/16x18 tap and appropriate drill bit.

if you try to rush this work you'll end up sliding off to the side. Stanless is hard to drill and drill bits are even harder to drill...so don't break one...by stepping up with so many drill bits you are less likely to get off center. center is deceiving as you'll see the end of the thread on one side and the bottom of the groove on the other. you'll have to trust that first drill bit. in this case the 1/4" one. PATIENCE is the key here. with that anyone can do this. you now have the knowledge, now get the experience. ;-)

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Old 06-05-2016, 12:11   #26
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Re: Rebedding formerly glassed bolts - Help !

On starting a hole in stainless--use a cobalt center drill, first; then a cobalt drill.

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Old 06-05-2016, 12:51   #27
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Re: Rebedding formerly glassed bolts - Help !

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On starting a hole in stainless--use a cobalt center drill, first; then a cobalt drill.

I use titanium bits. keep them cool...whilst drilling... and rust free. cobalt and carbide bits brake easily. in confined spaces and on the water..some rocking...and/or someone with little experience... a broken bit in the hole, is a whole 'nother can of worms. if you start small and step up gradually titanium works well. Now drilling stainless rolled tubing? cobalt for the pilot hole. thats some hard stuff. but once the hole is started titanium cuts right through.
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Old 06-05-2016, 12:54   #28
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Re: Rebedding formerly glassed bolts - Help !

oh the centering drills are nice tho if you have the right size.
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Old 06-05-2016, 13:49   #29
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Re: Rebedding formerly glassed bolts - Help !

OK. I have a lot to look into this weekend. This is great input. My usual tendency is to take the biggest hammer and chisel...

To clarify - two of the bolts look sheared at 1", one bolt is sheared at the head that I can't get out, the fourth one took a lot of effort to get loose, but I've thrown it away. Can't remember what it looked like, but all three of the holes that I can poke down into stop at 1 inch into something that feels solid. The test hole in the middle went down 1.3 inches and came up with nothing but fiberglass. Even smelled like fiberglass, though I think the first half inch is G10 (which is a just a solid fiberglass board, right?)

It is a Freedom with an unstayed mast, built in 1998, and I'm certain the step was built original at the factory. They were solidly built, so maybe it was overkill at the time because the connections on the panting rod look a little twinky. If there had been big forces, I would think over time this would have stressed it and it didn't seem snug when I removed it. On the other hand, this boat was lightly sailed over the years. Since I've been picking up the paces a bit, there have been things that have needed enforcing or have broken. I put the aluminum-casted gooseneck in both those categories and am working with a friend to machine a new one (another story for another time)

I'll try to drill into those holes where the bolts were. I know I can go another .33" more. They might just spin if I can't get a grip on anything but we'll see. I can feel down in there a bit, but just can't see anything so will try to figure out if I am hitting metal or not. Trust me. I am taking this slowly. It's so helpful that you all are taking this in baby steps with me, too. Stay tuned...

Oh, and the bolts are indeed .25".
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Old 06-05-2016, 13:56   #30
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Re: Rebedding formerly glassed bolts - Help !

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TOTALLY LOVE the drawing JM!
Yeah, so did I Except I wonder if that metal piece might be in two pieces just below the bolt holes on either side?
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