Re-installation of Screw Fastners Into Existing Holes

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Kovar
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Re-installation of Screw Fastners Into Existing Holes

Postby Kovar » Sun Feb 18, 2024 3:37 pm

On a 1988 Sport 13 I'm about to reinstall the wood after refinishing. I believe this is the first time the screws have been removed.

Q1:Once a screw fastener has been removed from the Unibond hull of a 1988 SPORT 13 Boston Whaler boat that once retained some wood component of the boat, is a complete “refilling” of the existing hole where the screw fastener was installed necessary before re-installing the screw fastener?

Q2: If “refilling” the hole where a screw fastener was installed before re-installing the screw fastener is required, what material is recommended for use in “refilling” the hole?

NOTE: I was not on planning to use new screws but I'm open to doing so if it's considered important.

Q3: Are “complete fastener kits” available?
Location: Westport, MA
1988 13' Whaler w 30 hp two stroke Johnson

jimh
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Re: Re-installation of Screw Fastners Into Existing Holes

Postby jimh » Sun Feb 18, 2024 6:02 pm

Kovar wrote:Q1:Once a screw fastener has been removed from the Unibond hull of a 1988 SPORT 13 Boston Whaler boat that once retained some wood component of the boat, is a complete “refilling” of the existing hole where the screw fastener was installed necessary before re-installing the screw fastener?
The need to re-work an existing hole into which a screw fastener that retained wooden components in a 1988 SPORT 13 boat to the Unibond hull depends complete on the condition of the fastener and its purchase into the Unibond hull.

There are two possible situations:
  • the screw fastener has a firm and appropriate purchase, or
  • the screw fastener did not have a good purchase, that is, there was a loose screw.

If the the situation is the screw fastener has a firm purchase, the only action needed will be to apply some suitable caulking material to the screw fastener so that its installation into the Unibond hull of your 1988 SPORT 13 boat is well sealed against ingress of water into the interior of the hull.

If the situation is the screw fastener does not have a firm purchase, that is, there is a loose screw, then the action needed will be to fill the existing hole with some epoxy resin mixed with a high density filler or perhaps with sawdust, let the epoxy resin cure to complete hardness, drill a new pilot hole into the filled hole, carefully pre-tap the hole with a sacrificial screw, then install the finish screw into the hole with some appropriate caulking material. In extreme cases, the size of the original fastener hole may need to be enlarged to get to solid material.

An appropriate caulking material is a suitable boat caulk--not a super strong adhesive sealant--such as BoatLife Caulk.

jimh
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Re: Re-installation of Screw Fastners Into Existing Holes

Postby jimh » Sun Feb 18, 2024 6:03 pm

Kovar wrote:Q2: If “refilling” the hole where a screw fastener was installed before re-installing the screw fastener is required, what material is recommended to for use in “refilling” the hole?
I answered this in my reply to Q1, see above.

jimh
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Re: Re-installation of Screw Fastners Into Existing Holes

Postby jimh » Sun Feb 18, 2024 6:04 pm

Kovar wrote:Q3: Are “complete fastener kits” available?
I have never heard of any vendor selling a kit of fasteners that was designed specifically for the re-installation of all the wood components in a 1988 SPORT 13 boat.

The fasteners used to fasten the wooden components of a 1988 SPORT 13 boat to the Unibond hull of the boat are not particularly unusual or specialized fasteners, and if you desire to replace any of then, you should be able to purchase an identical fastener of the same material, same quality, same size, same length, and same thread from any vendor that sells marine screw fasteners, or even at a well-stocked local ACE hardware store.

jimh
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Re: Re-installation of Screw Fastners Into Existing Holes

Postby jimh » Sun Feb 18, 2024 6:47 pm

Kovar wrote:I was not on planning to use new screws but I'm open to doing so if it's considered important.
To answer your implied question:
Q4: is replacement of all original fasteners that attached wood components on a 1988 SPORT 13 required?
I would not hesitate to re-use an original screw fastener as long as the original screw fastener was in good condition, that is, it was not not bent or deformed, the head of the screw where the tool would be applied is not deformed, and there is no corrosion on the material of the screw fastener.

Jefecinco
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Re: Re-installation of Screw Fastners Into Existing Holes

Postby Jefecinco » Mon Feb 19, 2024 9:16 am

Be aware of the different grades of stainless steel' corrosion resistance before buying.
Butch

Kovar
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Re: Re-installation of Screw Fastners Into Existing Holes

Postby Kovar » Mon Feb 19, 2024 9:30 am

Thanks for the reply. I can proceed with the job.
Sam
Location: Westport, MA
1988 13' Whaler w 30 hp two stroke Johnson

fno
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Re: Re-installation of Screw Fastners Into Existing Holes

Postby fno » Wed Feb 21, 2024 9:03 am

Stainless steel fasteners in grade 304 or 308 are found at Ace Hardware and other brick and mortar stores. They are exactly as described, that is, they will stain less than regular steel fasteners. For marine applications, 316 grade stainless fasteners are preferred for the long term. They can generally be found online or at McMaster-Carr.

jimh
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Re: Re-installation of Screw Fastners Into Existing Holes

Postby jimh » Thu Feb 22, 2024 10:38 am

Concern about the grade of stainless steel used in fasteners is often in relation to the boating area. If boating in tropical saltwater, corrosion in stainless steel may be more a problem than if boating in very cold freshwater.

fno
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Re: Re-installation of Screw Fastners Into Existing Holes

Postby fno » Thu Feb 22, 2024 7:11 pm

Good point JimH. I admit bias because I live in a salt water world in Florida. To be upfront, I do have some ACE Hardware fasteners on my boat and they are not showing signs of discoloration or fatigue. Mostly they are in dry areas of the boat and do not see a lot of salt water. The problem with hardware store SS fasteners is that they often do not describe the grade of stainless and usually come from a unknown third world country. Not that there is anything wrong with that. I am not a metallurgist but merely a machinist, so I would avoid 304 SS, accept 308, and prefer 316 for a saltwater environment. As for my supplier recommendation, you get what you get from ACE. If you buy from McMaster-Carr you are going to get first grade industrial quality fasteners. The cost difference will be minimal as well. To put some context to my recommendation, if you need screws fast, go to ACE and stock up. If you want long term quality and a forgot about it result go with quality fasteners from a reliable source that may take a day or two to deliver.