Filling and drilling holes using West System Epoxy

[Nicholson58]

Originally Posted by Sid at SailAway

My cat suffered some wind damage this winter on the Chesapeake. The binimi and framework were ripped off the boat by high winds. All the screws in the baseplates were basically ripped out of their holes. Fortunately, the frame was not bent.

My plan of attack was to oversize the holes to 1/4 inch. The holes as they are about an 1/8 inch. Number 8 selftappers came out. After that, I was going to take a bent rod and hog out some of the core to insure enough epoxy was introduced back in. Let it harden, pilot drill and then re-screw the frame back on.

I thought it was a good plan but wanted to get West Systems blessings on it. So, gave them a call and the tech told me the epoxy would be so hard that I wouldn't be able to screw the screws back in even with a pilot. I will be using 105 with the 205 hardener. I'm not buying it. Why wouldn't I be able to screw into the epoxy?

So, here's my question. Has anyone done this successfully? I would think this would be a common fix. Do I need to use a filler such as 404? If I hadn't called, I'd be fillin' and drillin' but he's got me scratching my head. What am I missing?

Absolutely! Oversize the holes - chip out some core. I usually use Marine-Tex. If the hole is through, duct tape the inside and then fill it. You can easily drill through with any drills. If you needed to thread, I often use gray Marine Tex. The filler makes it stronger. You can use ordinary machine taps for fitting machine screws. For wood or sheet metal screws you will need to drill the hole a bit over the root diameter or the screw will be very difficult to turn in.

[rwidman]

West System specifically says not to try this and 14 people suggest doing it anyway.

Through bolting is best. Other than that, how about using larger screws?

[keepondancin]

I agree with the West and colloidal silica, then drilling and tapping with machine screws. I have used this building small wood boats, with no problem. Also, on my Crealock 37, the canvas installer did the same thing with the dodger, drilling and tapping, claiming there was such a good layup in Pacific Seacraft construction, that is was the strongest way to install, other than backing plates. I am surprised that West didn't offer that solution, because, if I remember correctly, that is a method described in one of their tech bulletins. Don't use micro ballons or wood flower, no strength.

[skipmac]

Originally Posted by rwidman

West System specifically says not to try this and 14 people suggest doing it anyway.

Through bolting is best. Other than that, how about using larger screws?

I don't know who the OP spoke with at West Expoxy but their web site give specific instructions on various types of filling and drilling.

WEST SYSTEM | Use Guides - Bonding Hardware

Also detailed instruction from Maine Sail on drilling and filling with West epoxy but of course focused on through bolting which I think all agree is the best option if there is access to do so.

Sealing Deck Penetrations to Prevent Core Rot Photo Gallery by Compass Marine How To at pbase.com

[jaybird1111]

Here is another relevant article from West Systems, in addition to the two posted by skipmac:

Repairing Machined Holes in Fibreglass

[EmeraldCoastSailor]

I'd use keenserts so u have a proper threaded connection if u can't thru bolt.

[Cadence]

Originally Posted by Sid at SailAway

My cat suffered some wind damage this winter on the Chesapeake. The binimi and framework were ripped off the boat by high winds. All the screws in the baseplates were basically ripped out of their holes. Fortunately, the frame was not bent.

My plan of attack was to oversize the holes to 1/4 inch. The holes as they are about an 1/8 inch. Number 8 selftappers came out. After that, I was going to take a bent rod and hog out some of the core to insure enough epoxy was introduced back in. Let it harden, pilot drill and then re-screw the frame back on.

I thought it was a good plan but wanted to get West Systems blessings on it. So, gave them a call and the tech told me the epoxy would be so hard that I wouldn't be able to screw the screws back in even with a pilot. I will be using 105 with the 205 hardener. I'm not buying it. Why wouldn't I be able to screw into the epoxy?

So, here's my question. Has anyone done this successfully? I would think this would be a common fix. Do I need to use a filler such as 404? If I hadn't called, I'd be fillin' and drillin' but he's got me scratching my head. What am I missing?

You might try mixing glass micro balloons in the epoxy. A question, why reinvent the wheel? I'm sure there are many products sold that would do the job right out of the can or tube.

[Cheechako]

Realistically, on a Bimini, especially a large one.. you need to thru bolt those. If you have an overhead liner you could simply core out a 4" hole where you need one and put in a plastic screw out cover.
A lot of stress on a bimini in strong winds.
There are also white plastic snap in plugs available up to about 2" I think.

[DougAnnapolis]

I had same issue with screw mounted dodger. I drilld out hole to 3/8 inch. Put tape on the underside and filled with epoxy. Hardened expoxy was a bit proud of the deck so used small cone shaped grinder in my drill to make it flush with deck. Could not be thru bolted. Drilled pilot hole, applied boat chaulk and reattached with orig screws. Stronger than original installation

[anacapaisland42]

Try drilling a larger hole, epoxy in a piece of hardwood dowel and screw into that.
Bill

[Sid at SailAway]

Thanks to everyone for taking the time with all the reply's! I believe I can remove the headliner in the areas I need to expose. If so, I agree that thru-bolting would be the way to go. If not possible to get access, then I'll use the epoxy and filler method, pre-drilling the holes. Should start on this in a few days and will let you know how it goes, with pics....Thanks!

[Terra Nova]

Through......bolt!

[Cadence]

Originally Posted by Sid at SailAway

Thanks to everyone for taking the time with all the reply's! I believe I can remove the headliner in the areas I need to expose. If so, I agree that thru-bolting would be the way to go. If not possible to get access, then I'll use the epoxy and filler method, pre-drilling the holes. Should start on this in a few days and will let you know how it goes, with pics....Thanks!

Just a suggestion. You may want to consider a backing plate and a good sealant. The down side is, if it happens again it won't pull loose so the bows will bend.

Best of luck.

[DennisRyan]

....and now comes the defense.

I vote for West and screws instead of thrubolting. The reasoning: I'd rather have screws rip out instead of the superior holding power of thrubolting that could lead to bending the stainless frame in a real big blow. The screws are kinda sacrificial.

[GeneM]

Colloidal silica? Must be the same as fumed silica or cabosil - good thickener. Also add loose 1/4 inch chopped strands for strength and better tap screw holding. Thicken to peanut butter consistency. Through bolt is better, but not necessary if too difficult.