Hardware Re-bed - take 1

[ArmySailor]

Happy New Year Fellow Cruisers,

New Year, new projects... I'm facing my first deck bedding challenge. Can you help provide input on my assessment of damage and next steps??

Background: Last season I noticed a small brown spot that grew / creeped on deck from the end of a staysail fairlead track. It's black and rust colored, and about double the size of a quarter. Yesterday I removed the track (photos below)

-Track is about 24 inches long and held down by 8 pieces of hardware:
-6 screws penetrate the deck but do not go through
-2 are huge bolts that go completely through deck and are backed by steel disc, 3 inches diameter, about 1/2 inch thick, with nut and locking nut.

The backing assembly and 2 x thrubolts look perfectly fine. (photo of headliner, very minor rust mark, probably from salty air, not through the deck) The culprit is one hole under the very aft end "cap" of the track assembly. The cap is plastic. The bolt looked ok and not a rusty stump, as I was expecting. (I forgot to get photos of all the screws, but you can see the two bolts)

The balsa cored deck appears epoxied solid with the 2 big thrubolt holes - it's shiny when I use a flashlight.
The deck can't really be assessed for the 6 screw holes. No idea if they were driven through epoxied, as they should.

I thoroughly cleaned the deck and the track and plan to rebed using bed-it butyl tape, according to Maine Sail's fantastic primer on the subject.

Questions:

- do I need to do anything special to dry the deck besides ensure NO water ingress for awhile? (deck is covered for storage)

- do I need to inject epoxy into each hole, re-drill, fit, etc?

- the previous installation clearly had some kind of adhesive or sealant below the whole track. If I use butyl tape do I need to do this? Or is one benefit of butyl tape to focus on the hardware penetration and the surrounding areas? (ie not multiple inches of just track touching the deck)

-other things everybody else knows but I don't?

Thanks ya'll!





PS: If you're curious:
Dear boat is a 1979 Shannon 28, great vessel. I've had her 18 months now. Seaworthy, but I want to do a lot of repairs.
Related to this project, next project is to remove the staysail boom tack deck fixture - the boom on the staysail on a 28 foot vessel is simply more trouble than it's worth, and probably more dangerous than it's worth (I'm a single-hander). With properly sheeted staysail on these two tracks, it flops from one side to the other when I tack, needing only slight attention later. This gives me time to focus on jib and main, and whatever else. Suspect it can be a big help when beating in a narrow waterway... anybody want a staysail boom!?

[coopec43]

Surely it has to be some chemical reaction? Is the plastic breaking down?

Why Do Some Brands of Epoxy Resin Turn Yellow? – ArtResin

https://www.artresin.com/.../artresin/41958017-why-do-some-brands-of-epoxy-resin-t...
Aug 31, 2015 - ArtResin epoxy resin is properly stabilized against the degradative ... If you aren't using ArtResin epoxy resin then your work is in real danger of discoloration from the ... will generally reach its dark brown-yellow color within 24 hours. ... that the HDPE plastic bottles it comes packaged in does breathe a little, ...

Degradation of Various Plastics in the Environment

https://www.researchgate.net/publica...he_Environment


Why does plastic turn yellow? - Polymer Solutions

https://www.polymersolutions.com/blog/what-makes-plastic-turn-yellow/
Mar 7, 2016 - Plastic's longevity is one of the qualities that makes it such a useful material ... meant to remain outside the patient's body, the discoloration and failure were ... Exposure to UV radiation can cause plastics to change color (turn .... It's only been in the last 9 months that it's gone from nice white to a dark yellow.


Clive

[Uncle Bob]

Originally Posted by ArmySailor

Happy New Year Fellow Cruisers,

New Year, new projects... I'm facing my first deck bedding challenge. Can you help provide input on my assessment of damage and next steps??

Background: Last season I noticed a small brown spot that grew / creeped on deck from the end of a staysail fairlead track. It's black and rust colored, and about double the size of a quarter. Yesterday I removed the track (photos below)

-Track is about 24 inches long and held down by 8 pieces of hardware:
-6 screws penetrate the deck but do not go through
-2 are huge bolts that go completely through deck and are backed by steel disc, 3 inches diameter, about 1/2 inch thick, with nut and locking nut.

The backing assembly and 2 x thrubolts look perfectly fine. (photo of headliner, very minor rust mark, probably from salty air, not through the deck) The culprit is one hole under the very aft end "cap" of the track assembly. The cap is plastic. The bolt looked ok and not a rusty stump, as I was expecting. (I forgot to get photos of all the screws, but you can see the two bolts)

The balsa cored deck appears epoxied solid with the 2 big thrubolt holes - it's shiny when I use a flashlight.
The deck can't really be assessed for the 6 screw holes. No idea if they were driven through epoxied, as they should.

I thoroughly cleaned the deck and the track and plan to rebed using bed-it butyl tape, according to Maine Sail's fantastic primer on the subject.

Questions:

- do I need to do anything special to dry the deck besides ensure NO water ingress for awhile? (deck is covered for storage)

- do I need to inject epoxy into each hole, re-drill, fit, etc?

- the previous installation clearly had some kind of adhesive or sealant below the whole track. If I use butyl tape do I need to do this? Or is one benefit of butyl tape to focus on the hardware penetration and the surrounding areas? (ie not multiple inches of just track touching the deck)

-other things everybody else knows but I don't?

Thanks ya'll!





PS: If you're curious:
Dear boat is a 1979 Shannon 28, great vessel. I've had her 18 months now. Seaworthy, but I want to do a lot of repairs.
Related to this project, next project is to remove the staysail boom tack deck fixture - the boom on the staysail on a 28 foot vessel is simply more trouble than it's worth, and probably more dangerous than it's worth (I'm a single-hander). With properly sheeted staysail on these two tracks, it flops from one side to the other when I tack, needing only slight attention later. This gives me time to focus on jib and main, and whatever else. Suspect it can be a big help when beating in a narrow waterway... anybody want a staysail boom!?

Hi if it were me I would remove the core at each screw hole with a small bent nail and a battery drill, fill with a thick epoxy to the top of hole. this effectively creates a plug larger than the hole where the core was and when cured redrill and tap to replace screws with metal threads. I would also countersink all the holes to create an "o ring" of the chosen bedding compound between the track and deck. I would ensure that the entire track and ends had 100% bedding compound under them. The through bolts appear fine and should only require re bedding, also doing the countersink in the deck.
Not really that difficult or expensive and when done properly should never again leak.

[ArmySailor]

Cooper,

"it has to be some chemical reaction" - no, I'm not convinced it is. I'm much more concerned / convinced it has to do with the hardware. It's not just a general yellowing - if you look close it's a dark reddish brown.

Uncle Bob,

The holes for the screws (not the large thru-bolts) are very small. Not sure I can get a bent nail even in there. I'll see what I can do, though.

Any recommendations on bedding compound? Butyl tape ok?

Why are you recommending bedding along the entire track vs just the deck penetrations? There's 2-3 inches of nothing but track and deck between the holes. Not sure what benefit bedding is. Can you help educate me?

[Souzag818]

Big fan of the countersink, and by that I mean just a touch, not burying. 1/16"-1/8" bevel is all you need. Also love butyl tape under every fastener. Don't know why the whole track would need it. I am surprised that only two screws on the whole track are thru bolted. Plastic end caps should be the only ones with SMS, sealed with butyl of course

[roverhi]

Use a Dremel 199 bit and a Dremel type tool to rout out the core, Will leave a very small disfiguration of the gelcoat/deck around the fastener hole if cut in at as close to 90 degrees as you can manage.

Don't like the idea of a track that is screwed down. Apparently it's worked okay but scares me that they could pull out.

Probably best to bed the track with butyl to cut down corrosion of the track. As Souzag says, bevel the edge of the fastener holes with a counter sink. It makes a donut of caulk where the fastener passes through which will be way less prone to failure with any movement of track or screw/bolt.

[Uncle Bob]

Originally Posted by ArmySailor

Cooper,

"it has to be some chemical reaction" - no, I'm not convinced it is. I'm much more concerned / convinced it has to do with the hardware. It's not just a general yellowing - if you look close it's a dark reddish brown.

Uncle Bob,

The holes for the screws (not the large thru-bolts) are very small. Not sure I can get a bent nail even in there. I'll see what I can do, though.

Any recommendations on bedding compound? Butyl tape ok?

Why are you recommending bedding along the entire track vs just the deck penetrations? There's 2-3 inches of nothing but track and deck between the holes. Not sure what benefit bedding is. Can you help educate me?

Hi, if the holes are too small then drill them out a bit, the bent nail only needs to be a thin one, head end bent about a 1/4 inch to enable the core to be reamed out beyond the hole so that when the thickened epoxy is added it forms a plug extending beyond the edge of the hole. Fill hole level with deck and when cured drill the hole into the epoxy plug and tap the thread.
I would bed the entire track, I believe butyl would be fine, to ensure no water gets under it and starts to corrode. Butyl is cheap, track not so. As I said earlier, the small countersink is to allow the bedding to form an "o ring" type seal around the fasteners between track and deck. I think I would look into new plastic end fittings as well, if only for aesthetics.
Cheers

[Richard5]

If it were me I would use HDPE dowels with either ABS glue or cyanoacrylate adhesive to bond the dowel to the deck substrate. Drill pilot holes in the dowels for each screw. Both the glue and the adhesive have gap filling qualities and are resistant to solvents. Do this step before removing the rust stains in order to avoid liquids from running into the screw holes.

For removing rust stains use either muriatic acid or a poultice of baking soda and white vinegar with elbow grease and stiff nylon bristle brush. Some folks talk glowingly of a product called Barkeepers Friend.

Be careful to avoid contacting metal with the muriatic acid. Avoid inhalation of the fumes.

[Souzag818]

Originally Posted by Richard5

If it were me I would use HDPE dowels with either ABS glue or cyanoacrylate adhesive to bond the dowel to the deck substrate. Drill pilot holes in the dowels for each screw. Both the glue and the adhesive have gap filling qualities and are resistant to solvents. Do this step before removing the rust stains in order to avoid liquids from running into the screw holes.

For removing rust stains use either muriatic acid or a poultice of baking soda and white vinegar with elbow grease and stiff nylon bristle brush. Some folks talk glowingly of a product called Barkeepers Friend.

Be careful to avoid contacting metal with the muriatic acid. Avoid inhalation of the fumes.

Muriatic acid is pretty harsh and toxic. I wouldn't use it. Oxalic acid,which can be bought online very cheaply, will clean up rust stains easily without the dangers of muriatic acid. That's why Barkeepers Friend works, cause it contains oxalic acid. It's also the main ingredient of teak bleach, so if you have any unfinished teak, it'll lighten it and make it golden again. And unlike muriatic acid, you can mix some with water to take rust stains off stainless steel without hurting it.

[GordMay]

Originally Posted by Souzag818

Muriatic acid is pretty harsh and toxic. I wouldn't use it. Oxalic acid ...

I too, would prefer Oxalic Acid.
Muriatic acid isn't pure hydrochloric acid (HCL), nor is there a standard concentration. It's important to check the product label to know the concentration, because the chemical is highly corrosive and also reactive. Some industrial suppliers offer muriatic acid that is 31.5 percent HCl by mass (20 Baumé). However, other common dilutions include 29 percent and 14.5 percent.
If used for cleaning purposes, muriatic acid should be no stronger than about 10% concentration. As noted, be careful around metals (thorough rinse).

[WSMFP]

I just did this exact job and ran a strip of 1 inch wide butyl tape under the entire track. The excess will squeeze out when bolted and can be easily removed with a razor blade.

[ArmySailor]

Originally Posted by WSMFP

I just did this exact job and ran a strip of 1 inch wide butyl tape under the entire track. The excess will squeeze out when bolted and can be easily removed with a razor blade.

Perfect, thank you. Did you get at the core a bit and re epoxy first for each hole? Did you bevel the top of the holes? I'm thinking this is a simple job but like anything boat related there seems to be a fetishism of complexity. :/

[ArmySailor]

Originally Posted by Richard5

If it were me I would use HDPE dowels with either ABS glue or cyanoacrylate adhesive to bond the dowel to the deck substrate. Drill pilot holes in the dowels for each screw. Both the glue and the adhesive have gap filling qualities and are resistant to solvents. Do this step before removing the rust stains in order to avoid liquids from running into the screw holes.

For removing rust stains use either muriatic acid or a poultice of baking soda and white vinegar with elbow grease and stiff nylon bristle brush. Some folks talk glowingly of a product called Barkeepers Friend.

Be careful to avoid contacting metal with the muriatic acid. Avoid inhalation of the fumes.

What is the logic behind dowels and super glue ?? (I had to Google cyanoacrylate adhesive you recommended). I've poured over Don Casey's this old boat, and mainesail - no mention of dowels. I'm always open to considerations, just looking for details. I read about ABS glue - doesn't look like it should be used for this. Correct me if I'm wrong.

How do I size dowels correctly? Sanding? Do I enlarge the holes in the deck for each screw? PS this won't be my last bedding project... I'm certain.

[Richard5]

Originally Posted by ArmySailor

What is the logic behind dowels and super glue ?? (I had to Google cyanoacrylate adhesive you recommended). I've poured over Don Casey's this old boat, and mainesail - no mention of dowels. I'm always open to considerations, just looking for details. I read about ABS glue - doesn't look like it should be used for this. Correct me if I'm wrong.

How do I size dowels correctly? Sanding? Do I enlarge the holes in the deck for each screw? PS this won't be my last bedding project... I'm certain.

Because the HDPE offers a greater purchase, or 'bite', for screw threads. And it can be drilled very well as in the case of through bolts. I was thinking of the anticipated loads exerted on the track and am not sure epoxy would be sufficient. I think the modulus of elasticity of the epoxy is not great plus epoxy is not good when in shear. The adhesives I mentioned are the best to use with HDPE.

I suppose you could sand the dowels to proper diameter, use coarse grit if you do. I would drill the substrate to proper diameter. Didn't your say there was damaged substrate surrounding the existing screw holes?

Also, isn't this project necessary because there was insufficient securing of the track plus water ingress? HDPE provides the holding power plus eliminates the source of leaks.

As for muriatic, I have been remiss to not have mentioned the dilutions as noted by Gord. I have had great results with both muriatic and oxalic acids. My suggestion of muriatic was to 'bypass' the oxalic in this case; that muriatic is more aggressive/less dwell time. Obviously, experience is required.