Best filler for holes

[bob_77903]

The PO took the screws out of the 24"x24" deck hatch and replaced them with bolts that now run thru the decks with nuts below. He had to remove the teak trim to do so. I would like to fill in the holes and go back to OEM type screws to rebed the hatch frame back to the deck. What is the consensus on the best filler to use so i'll be able to run screws back into it? The Hatch is a Atkins & Hoyle if it makes any difference.

[SkiprJohn]

Aloha Bob,
If you are certain that is what you want to do I would drill out the bolt holes to accept a standard size hardwood dowel then epoxy the dowel in place, wait for the epoxy to dry and then cut or sand the ends of the dowel off. When screwing down the hatch I'd drill proper sized pilot holes and bed the hatch with polysulfide and then screw it down.
Don't you find the through bolts to be more secure?
Kind regards,
JohnL

[bob_77903]

I'm sure that YES the bolts are definitely more secure John, but with the bolts - nuts and flat washers sticking down 3/8" into the cabin. its a tad unsightly, let alone not being able to install the teak trim around the opening. I would assume that Tartan would have used bolts if they thought it was an issue. I talked to Atkins & Hoyle and they didn't try to dissuade me from filling and rescewing, but am open to suggestions.

[bob_77903]

Oh, and Aloha back atya John

[bob_77903]

Another option could be using RIVNUTS below counter sunk into the deck. Anybody used this method?

[AnchorageGuy]

Originally Posted by bob_77903

Another option could be using RIVNUTS below counter sunk into the deck. Anybody used this method?

I have used these in the past with success. But mostly in areas that were hidden. They can be made flush and then add the trim ring over them. The bolts would just have to be well bedded.

[roverhi]

Riv nuts are aluminum. From what I hear they corrode around teh SS fasteners and are impossible to remove the fasteners after that. The dowel sounds like the most secure way to affix the hatch.

Aloha
Peter O.

[stevensc]

if the bolts protrude into the cabin 3/8" you could make new trim 1/2" thick wherever a bolt is drill it partway though making pockets so it will fit over the bolt protrusion, then fasten the trim as you normally would. if you can live with 1/2 thick trim it should work.
good luck
Steve

[bob_77903]

Thanks Steve, am considering that....by the way do you know Amos Moses, course he's bout 45 minutes SE of Thibodaux , La

[AnchorageGuy]

Originally Posted by roverhi

Riv nuts are aluminum. From what I hear they corrode around teh SS fasteners and are impossible to remove the fasteners after that. The dowel sounds like the most secure way to affix the hatch.

Aloha
Peter O.

The ones we have always used are steel.

[bob_77903]

If i can get steel rivnuts i believe that's the way I'm going to go Chuck...thanks for the update. I think they also have rivnuts with little spikes in the flange that dig in to keep them from turning. I'm pretty sure there steel.

[AnchorageGuy]

Originally Posted by bob_77903

If i can get steel rivnuts i believe that's the way I'm going to go Chuck...thanks for the update. I think they also have rivnuts with little spikes in the flange that dig in to keep them from turning. I'm pretty sure there steel.

You are correct. I believe the last time I bought those I got them from Challenge Sailcloth. They are used a lot in upholstery work.

[MidLandOne]

Originally Posted by bob_77903

I think they also have rivnuts with little spikes in the flange that dig in to keep them from turning. I'm pretty sure there steel.

If I am thinking of the same thing as you, in this part of the world those are called Tee Nuts. They are not riveted in as a Rivnut is though, they just rely on the spikes to prevent rotation when the screw is tightened into them. I have only seen them in zinc plated (ie not hot dipped) steel, but that is not to mean other materials don't exist.

Rivnuts I have only seen in steel and aluminium but that does not mean other materials are not available though.

All those materials are unsuitable in my view.

My experience is that screwing into small diameter fillings of wood or thickened epoxy is not reliable due to the small volume of the filler material and its non-homogeneity with the close by deck material (am assuming that is fibreglass) resulting in the likelihood of the filler cracking, but my hands on experience in such small repairs is not great. I would personally get some face to face professional advice on it - I also wonder if you have had a hunt though all the advisory material on the West Systems internet site www.westsystem.com.

Given that bolts exist and they are the most secure fastening method I would try to go down one of the following tracks myself -

There may be the possibility of a solution using visible stainless steel dome nuts on the existing bolts as is often done even on high quality timber or timber/fibreglass composite boats when the underside of the deck is the finished inside timber surface and deck fittings are bolted through from above ie there is no lining to hide the nuts.

Otherwise providing another teak trim if a trim is required to hide raw unfinished edges etc about the hatch cut out but I appreciate if that is required to cover the nuts then that poses another fixing challenge if you don't want fasteners showing on the trim and future access to the nuts is to be maintained (although you could possibly capture the nuts in fibreglass so that future access is not, hopefully , required to them if the bolts later need to be withdrawn for hatch maintenance).

[Stevens 47]

Follow this link to SS Tee Nuts. McMaster-Carr

For a filler I use epoxy with milled fibre and glass bubbles, from my experience it takes self taping machine screws. Make the milled fibre into a wet thick paste with the epoxy, the glass bubles gives the mixture a good workable body mix in enough to stop it from slumping. You would need to over drill the hole and make sure that you use the correct sise drill much same as you would for self taping into steel. You can use the same mixture to create a core if you decide to thru bolt in some way, a good idea. I personly preffer not to use any type of material that will rot with any mechanical fastener.

Threaded Inserts
This product matches all of your selections.



Part Number: 90973A116 $9.92 per Pack of 10
Type
Knock-In
Knock-In Type
Tee Nuts
Tee Nut Type
Standard
For Use With
Plastic, Wood
Application
Create New Threads
Material
Stainless Steel
Stainless Steel Type
18-8 Stainless Steel
Finish/Coating
Plain
Threaded Type
Right-Hand Threaded
System of Measurement
Inch
Internal Thread Size
5/16"-18
Internal Thread Fit
2B
Drill Size
13/32"
Base Diameter
7/8"
Barrel Diameter
.391"
Barrel Height
1/2"
Number of Prongs
4
Rockwell Hardness
Not Rated
Minimum Tensile Strength
Not Rated
Specifications Met
Not Rated
Installation Instructions
Drill a hole to fit the barrel, insert tee nut, and hammer in the prongs until the base of the tee nut is flush with the surface.

[AnchorageGuy]

That is the one. But the rivnuts can also be found in steel and stainless.