1967 13-footer Bow Eye Repair

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
25inland
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Joined: Sun Apr 10, 2022 3:05 pm

1967 13-footer Bow Eye Repair

Postby 25inland » Sun Apr 10, 2022 4:36 pm

I recently acquired a 1967 13-footer with a damaged bow eye fitting. The bow eye had been ripped through the hull. This damage was then poorly repaired.

bowEyeDamage1.jpg
Fig. 1. Poor repair of bow eye damage at bow stem.
[Later comments explain the original location of the
bow eye is seen below the bolt, with the bolt having
been placed in a newly drilled hole in a different
position on the stem.]
bowEyeDamage1.jpg (11.66 KiB) Viewed 1737 times


bowEyeDamage2.jpg
Fug. 2. Poor repair of bow eye damage at cockpit.
bowEyeDamage2.jpg (22.84 KiB) Viewed 1737 times


Give me suggestions on how to properly repair the damaged hull and replace the bow eye

Oldslowandugly
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Re: 1967 13-footer Bow Eye Repair

Postby Oldslowandugly » Sun Apr 10, 2022 4:56 pm

I suggest this procedure:

  • remove any remains of the bolt
  • hog out the hole [enlarge the hole to remove any damaged material]
  • fill the hole with fiberglass resin or epoxy resin, which will soak into all the spaces
  • or use MarineTex, which may be stronger, but will not soak into all the spaces
  • drill a completely new hole
  • mount a a new bow eye set.

ASIDE: the Norman pin looks like it cracked its mount. Removing the pin is a tough job, but removing the Norman pin is the best way to repair the area.
  • Spread the crack
  • glue with fiberglass resin
  • fill the hole like the bow eye
  • drill a new mounting hole.
This repair is a big job but the repair is necessary.
Last edited by Oldslowandugly on Mon Apr 11, 2022 10:16 am, edited 1 time in total.

jimh
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Re: 1967 13-footer Bow Eye Repair

Postby jimh » Mon Apr 11, 2022 6:15 am

For advice on how to make repairs to the Unibond hull of a Boston Whaler boat, read the factory instructions, which are reproduced in the REFERENCE section at

https://continuouswave.com/whaler/refer ... tions.html

I don't know exactly what was meant by the term used above to "hog out the hole", but I would not unnecessary enlarge the original hole, and particularly I would not use a drill to make a very big enlargement of the hole in the hull at the bow stem through which the threaded rod for the bow tow eye passes.

I would not use Marine-Tex to make this repair, nor would I use "fiberglass resin" which I presume meant to identify polyester laminating resin. For this repair you want an excellent, strong adhesive that can make excellent bonds to materials like cured fiberglass and foam: that will be epoxy resin.

A good source for a small quantity of epoxy resin and filler materials is the WEST System Fiberglass Repair Kit. Epoxy resin makes a superior bond to materials like fiberglass laminates and foam compared to polyester laminating resins. The kit includes pre-measured amounts of resin and hardener, filler materials, which insure a perfect mixing ratio and complete cure of the reagents. Small pieces of fiberglass cloth and filler material are also included. The kit is a good value and can be used to make multiple repairs. The resin and harder are in sealed packets and will last for years on the shelf. There will be no guessing about mixing ratios or loss of shelf life from opening a jar of resin.

If there is any cracking of the gel coat layer at either inboard or outboard ends of the hole in the bow stem, all loose material should be removed. Follow the procedures in the factory instructions for repair of cracks. Consider laminated some additional cloth to add strength to the hull at each end of the hole. Damage to the hull or deck at the ends can be repaired as directed in the factor repair instructions.

Depending on the amount of damage or enlargement to the hole, coat the walls of the hole with epoxy resin, or if necessary to better fill gaps, epoxy resin mixed with some filler. Do not completely fill the hole, just coat the walls of the hole and fill any areas missing original laminate or foam. When fully cured, re-drill the hole to its original size. Verify that the drilled hole has no gaps in its wall. If it does, use epoxy resin to fill any voids in the hole, allow the resin to cure fully, and re-drill again to original size.

The bow stem as see in Figure 1 looks like it was nicely repaired already at the exit hole area.

The prior repair appears in Figure 2 to perhaps have added a backing plate to spread the load of the bow eye over a larger area. That is a good technique to prevent any future problem with the bow eye being pulled out of the hull.

A new bow eye and new lifting eye can probably be obtained from off-the-shelf marine components. A threaded rod to match the threads in the bow eye and lifting eye should be stainless steel. Contact Sue at Twin Cities Marine in Wisconsin for advice on getting OEM-quality parts.

Oldslowandugly
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Location: Queens NY

Re: 1967 13-footer Bow Eye Repair

Postby Oldslowandugly » Mon Apr 11, 2022 8:44 pm

To "hog out the hole" means to remove any damaged glass fibers or resin that a moving fastener may have caused.

When I replaced a bow eye set I witnessed a lot of damage to the surrounding area due to movement of the bolt. Fiberglass is really called FRP or Fiberglass Reinforced Plastic. The concept is the same as reinforced concrete. The glass fibers used to strengthen the plastic are just as susceptible to fracturing as any glass product. The plastic resin can also be cracked and fractured by the movement.

[To "hog out the hole"] use a tool like a rasp and ream out the hole trying to scrape away any damaged fiberglass to leave only solid material. If it enlarges the hole somewhat that is fine since you are going to fill it anyway. This also roughs up the surface to provide good "tooth" for the filler. You don't want to rely on damaged material that the filler may not reach or adhere to solidly.

jimh
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Re: 1967 13-footer Bow Eye Repair

Postby jimh » Tue Apr 12, 2022 9:58 am

Many thanks for the lengthy and detailed definition of "hog" as in "hog out the hole."

All my prior experience with the term "hog" in relation to boats was to indicate a distortion in the shear line of a hull caused by improper loading, See definition 2 below

At M-W.COM, "hog" is defined:
    HOG, transitive verb
    1. to cut (a horse's mane) short;ROACH
    2. to cause to arch
    3. to take in excess of one's due; hog the credit
    4. to tear up or shred (some material, such as waste wood) into bits by machine

Your unusual usage seem to be generally similar as defined in 4 above. I have never hear "hog" used in that manner before. I have heard the expression "bush hog", a powerful mowing machine able to cut away plants with wood stalks, which conforms exactly to the meaning in 4 above.

I continue to advise that unnecessary enlargement of the diameter hole is to be avoided. A better approach to filling the hole with new material might be to use an improvised cutting tool such as a small Allen Wrench to create a relief or pocket of space under the laminate material at each end, then fill that space with epoxy resin mixed with high-density filler. This will give more strength to the laminate at each end of the hole. This method is discussed at

https://continuouswave.com/forum/viewto ... 224#p18406

and from that article I borrow this illustration:

Image
Fig. 3. Using improvised tool to create a void or pocket under the laminate layer for the purpose of strengthening the repair area.

I give a long narrative of making repairs with epoxy resin at

Minor Repairs With Epoxy
https://continuouswave.com/maintenance-logs/epoxy/

Repairs that I made with epoxy resin to my 1976 SPORT 15 boat in 1997 are still in place, 25-years later, which I think speaks well for the method used. In that article, I comment about the ease with which abrasion can remove old laminates. This is a caution that deserves repeating: when repairing older Boston Whaler boat the rate at which abrasion can remove old gel coat and laminate material is surprising; go easy when using metal tools--especially a rasp.

Oldslowandugly
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Re: 1967 13-footer Bow Eye Repair

Postby Oldslowandugly » Tue Apr 12, 2022 4:58 pm

The Allen-wrench-approach jimh just described would be the exact definition of "hog out" used at Shadetree Mechanics University.

dtmackey
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Re: 1967 13-footer Bow Eye Repair

Postby dtmackey » Wed Apr 13, 2022 9:27 am

IMPORTANT in this repair. When filling in the void made by the methods described above, it is a good idea to place a plastic drinking straw to provide a pilot hole to follow when re-drilling the hole for the bow eye. Without a guide, the slightest angle of the drill could have you exit the other side in an undesirable area. I've done enough of these over the years to know. Also placing a large 316 stainless fender washer on the inside helps spread the load.

Hope this helps.

D-

25inland
Posts: 8
Joined: Sun Apr 10, 2022 3:05 pm

Re: 1967 13-footer Bow Eye Repair

Postby 25inland » Wed Apr 13, 2022 4:39 pm

dtmackey wrote:IMPORTANT in this repair. When filling in the void made by the methods described above, it is a good idea to place a plastic drinking straw to provide a pilot hole to follow when re-drilling the hole for the bow eye.
I was actually really worried about drilling the hole straight, I think you saved my bacon.

For filling the bulk of the hole, would a higher density poured foam work in addition to the epoxy repair?

The previous owner appears to have patched the original hole for the tow eye and just relocated the hole closer to the Norman Pin [as illustrated below in Figure 4].

fig4a.jpg
Fig. 4. Damage and repairs near Norman Pin base seen in close-up view.
fig4a.jpg (63 KiB) Viewed 1582 times


As for the Norman Pin, that little bronze nut and washer above the stem repair seem to line up with the Norman Pin. There looks to be fairing compound on the Norman Pin area so I suspect it's a repair by the previous owner.

fig5a.jpg
Fig. 5. Damage at bow gunwale.
fig5a.jpg (30.25 KiB) Viewed 1582 times


I think I will grind down the stem, then repair a bit, then [add laminate] to reinforce [the stem], then patch the cockpit end as Jim and Oldslowandugly suggested.

jimh
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Re: 1967 13-footer Bow Eye Repair

Postby jimh » Thu Apr 14, 2022 7:59 am

The view of the foredeck in Figures 2 and 4 show significantly different amounts of damage. The view seen in Figure 4 shows more defects in the gel coat and residue of what appears to be wood that was adhered to the cockpit deck.

Figure 5 shows a generally rough condition.

You have a lot of work ahead.

Restoration of the gel coat in the cockpit may be impossible. Watch this demonstration presentation showing refurbishment of the cockpit of a Boston Whaler boat in which an entirely new top coat is applied to cover the original laminate and gelcoat:

Boston Whaler Crazing Repair
https://www.youtube.com/watch?v=4tZDBOYqdfA

I suspect that in the above-linked three-minute presentation the work shown probably took 40-hours to actually perform.

jimh
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Re: 1967 13-footer Bow Eye Repair

Postby jimh » Thu Apr 14, 2022 8:13 am

dtmackey wrote:When filling in the void made by the methods described above, it is a good idea to place a plastic drinking straw to provide a pilot hole to follow when re-drilling the hole for the bow eye.
That is a brilliant idea.

dtmackey
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Re: 1967 13-footer Bow Eye Repair

Postby dtmackey » Thu Apr 14, 2022 9:15 am

25inland wrote:...for filling the bulk of the hole, would a higher density pour foam work in addition to the epoxy repair?
Foam for structural integrity on something like hardware where forces are isolated to a small area is not the direction I'd go. Even a dense poured foam is only foam, if the boat is towed, there can be significant forces against the the inner skin that would then use the foam as the material to displace the force into the hull.

I'd go with epoxy or polyester resin and you can mix with cabosil or another filler material so it's easier to work with and not too viscous. Since the holes are elongated, putting a fiberglass patch over the skin would be a good idea.

D-
Last edited by dtmackey on Thu Apr 14, 2022 12:02 pm, edited 1 time in total.

jimh
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Re: 1967 13-footer Bow Eye Repair

Postby jimh » Thu Apr 14, 2022 9:50 am

If the original hole for the rod that connects the bow eye to the lifting eye has been covered over and filled, re-drilling that hole will have to be done very carefully. The new hole should be started at the bow stem end, as that will be the most critical alignment. Choosing the exact angle for the hole so that it exits at the desired location on the cockpit end perhaps can be assisted if a drilling template or guide is fabricated.

Starting with a very small diameter (and very long drill bit) may be the best way to begin.

If you can remove the prior repairs and discover the exact location of the original hole at the stem and at the cockpit ends, that would be a good guide for the new hole.

I don't know if what I am about to say is workable: after finding the original hole at the stem, perhaps if you made a short exploratory hole at the approximate angle needed, you could then shine a strong laser light beam into the hole, while wrapping a black cloth around the hole and lamp to prevent any light from escaping at that end; then, in an extremely dark environment, you might possibly be able to see that light beam from a short exploratory hole drilled at the cockpit end. This could give you some guidance about the necessary angle for the drilled hole.

Oldslowandugly
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Re: 1967 13-footer Bow Eye Repair

Postby Oldslowandugly » Thu Apr 14, 2022 10:15 am

dtmackey wrote:IMPORTANT in this repair. When filling in the void made by the methods described above, it is a good idea to place a plastic drinking straw to provide a pilot hole to follow when re-drilling the hole for the bow eye.
That is probably the smartest idea I have seen in years. [By using the drinking straw] a pilot hole that is straight and true will be cast into the filler material. Kudos!

Figure #4 shows some serious enlargement of the original hole as well as broken gel coat all over the immediate area.
I see a LOT of damage that needs to be removed. Best to get it all out. Is the blue area gel coat or old paint?

A very coarse sanding disc on an angle grinder will make quick work of all that loose damaged materiel.

You can layer the new fiberglass in a bit at a time.

I like to add a new layer just as the previous layer is still tacky.

Woven glass cloth is easier to use on large flat surfaces but glass mat is easier on small areas and curves. You can push it around and form it with a small paint brush loaded with resin. Don't try and get it perfect at first. You will need to grind it down and fair it later.

Remember that the FRP is structural and has to be as strong as possible.

Later on fairing can be done with a glass-reinforced BONDO type filler such as [Gorilla Hair]. Just be aware that the glass dust is very itchy and wear eye protection, gloves, and overalls.

I think you are going to end up painting that area later.