What is behind the screws for the rear loops?

[shorefun]

I decided to mess with these eyelets that are on the back of the sunfish. The one screw head broke off.
I got two others out fine. These are not wood screws but some sort of self tapping machine screw. This is a 1998 era Person built hull.
I am making an assumption it is just going into thick fiberglass.
Does anyone have experience with this problem and which solution works?

thanks

 

[beldar boathead]

I think the Pearsons have aluminum plates. There is definitely something there more than fiberglass! Plus the screw head breaking off implies that the screw must have had some corrosion with the plate in the hull.

 

[L&VW]

I decided to mess with these eyelets that are on the back of the sunfish. The one screw head broke off.
I got two others out fine. These are not wood screws but some sort of self tapping machine screw. This is a 1998 era Person built hull.
I am making an assumption it is just going into thick fiberglass.
Does anyone have experience with this problem and which solution works?
thanks

I have experience with this, and I've found...
If it ain't broke, don't try to fix it!

OK... ...Solutions...

1) You can go to the next size machine screw, drill for that size, and use a tap to rethread the plate.

2) Move the eye strap over ⅜- to ½-inch, and drill/tap for the same-sized machine screw. Drill slowly, starting with smaller sizes—we don't want the plate to dislodge or bend . Put anti-corrosion paste in the hole and on the machine screw. (Or waterproof grease, if that is what's handy).

3) Access the eye strap's underside by cutting through the hull bottom. Re-tap the existing hole or enlarge the hole for a nut and bolt of the same size. Tighten the bolt and rebuild the hole in the bottom.

4) I see one screw head has broken off. Since the screw is stainless steel, drilling it out is quite an exercise! I'd keep the existing (good) machine screw, and rotate the eye strap to a new location, and proceed as below:

Insert a Toggler™ toggle-anchor ($5). To do so, drill out the hole and backing plate to fit. Reverse it on its plastic insertion device (included), secure it (for now) with epoxy. Wrap a threaded rod (one that fits the new threads) with electrical tape, insert it, and back-fill the hole with an epoxy mix. Once cured, remove the threaded rod and install the eye strap back into its new location. No taps needed.

To make the other side match is more work, but an option.





6) Reverse both sides: I don't see any harm in using sheet metal screws—providing the plate is present and drill-able.

 

[signal charlie]

Aluminum plate like Beldar said. Go with L&VW's solution 1.

 

[shorefun]

Me being the curious sort of person.

I took my electrical meter out and found out the Al plate is just below the thin upper deck glass.

I might enlist my brother to get this screw out. He is a mechanic by trade an after 50 years knows a thing or two about getting stuck screws out without messing up the plate.

So I will attempt to get the screw drilled out without hurting the Al plate then go back in with 8/32 machine screw.

If that does not work I will likely go larger and use my lathe to make the head of the screw fit better.

Thanks for your help.

 

[L&VW]

Aluminum plate like Beldar said. Go with L&VW's solution 1.

Yes, my Sunfish is a '77. Moved SC quote:

I think L&VW might get away with that repair, esp on an older boat where the fiberglass is just a bit thicker. We had a boat for years that just had bigger screws for the bridle eyestraps, the deck was thick enough to hold the screws plus we put in a squirt of 3M 4200.

The anchor remedy is extreme, it leaves a big hole. The meatal will also rust quickly and size up any fastener. I'd consider looking at the similar plastic anchors or I have used screw in plastic drywall anchors to fix the cockpit toerail on a Barnett Butterfly....after muttering unkind words about the corroded molly bolts I had to cut off

Skipper tested them out, they worked great.

The toggle I suggested is stainless steel. ;

 

[L&VW]

Missed shorefun's reply by 1 minute!

The difficulty with drilling begins with what's left behind. I'd leave that damaged machine screw for your professional.

 

[signal charlie]

Stainless, if not high quality marine grade, in my experience, has = sawzall

OTOH good marine stainless through nylocks is a dream to work with!

 

[shorefun]

So my brother is a professional mechanic with some amazing skills.

I have done some car restoration work. I am in the process of rebuilding a 1931 Model A Ford Cabriolet from basically junk.

The skill level here and tools available are not normal.

My brother had the eye for running a drill straight and parallel, well I can do it to, but he is better at it.
A secondary technique is a diamond bit tool for a Dremel. that lets you eat away at just the metal you want.

So the initial hope is to get it drilled down the middle and work up to larger bits. That does not always happen, but sometime you get lucky it is worth a try.

The next step is to keep the oversize small enough I can tap out to a 10/32 and just go up one size.

We will just work it and see.

My initial question was what was down in the hole. I could not tell if I was dealing with 1" block of fiberglass or wood. Then when you guy said it was a plate the next question was how deep. Once I found it is just on the other side of the dull deck then it becomes simpler. Trying to go straight down a hole on a little screw is just not going to happen. It will be hard enough getting centered with little depth there is now.

I need to take a closer look at an Opti with some curing glass. I am hoping to get gel coat on it this weekend in the nice warm weather.

 

[L&VW]

The skill level here and tools available are not normal.

My brother had the eye for running a drill straight and parallel, well I can do it to, but he is better at it.
A secondary technique is a diamond bit tool for a Dremel. that lets you eat away at just the metal you want.

So the initial hope is to get it drilled down the middle and work up to larger bits. That does not always happen, but sometime you get lucky it is worth a try.

The next step is to keep the oversize small enough I can tap out to a 10/32 and just go up one size.

We will just work it and see.

My initial question was what was down in the hole. I could not tell if I was dealing with 1" block of fiberglass or wood. Then when you guy said it was a plate the next question was how deep. Once I found it is just on the other side of the dull deck then it becomes simpler. Trying to go straight down a hole on a little screw is just not going to happen. It will be hard enough getting centered with little depth there is now.

I need to take a closer look at an Opti with some curing glass. I am hoping to get gel coat on it this weekend in the nice warm weather.

7) A Dremel™ can also be used to cut a slot in the broken-off machine screw body. I'd drill one or two ⅛-inch holes on either side, and introduce corrosion-fighters Kroil™, CDC™, PB-Blaster™, or WD-40™ at the aluminum backup plate. Let the liquid "work" for a few days, and then try to "work" the screw (back and forth), then out, finally.

 

[shorefun]

I appreciate the suggestions. Let me explain my thoughts/ experiences and what my preferred method will be.

Done the dremel slot many times.

Here it will create more damage on the glass then what I want. Plus if the stainless is that stuck in the aluminum plate it just will not work.
Getting the, pick your oil, to the plate will be hard and could mess up the glass in the area. My brother the mechanic has tried all of them and pretty much if the liquid can get in then they will come loose anyway. If the part is that corroded that it will not come loose then you can not get the liquid to get into the area. I even tested this with a 1931 Model A Ford engine block. The studs needed to come out. I put Kroil on for a week twice a day. Then my brother came over with his fancy stud tool. Then he looked at the studs and marked the ones he knew were going to break. Every stud that came out was fully dry, no penetration of the fluid. Every stud by brother said would break did. There was erosion at the base of the stud so that is how he knew they were going to break.

What does work is heat cycles or beating the shaft. Back to my first part I do not want to make the slot into the glass. So I will drill and grind it out.

The short distance the plate is below the glass means I can be pretty accurate in getting a drill in the center. The diamond grinder I have is small enough to get into the hole so between the two I feel I can get the screw out and a hole that will take a screw. Will the threads be useable, there is a good chance the will not be, but even at this point the threads may not be good with corrosion.

On a nice day, my brother and I will tackle the problem.

A nice warm day today. I put down some gel coat on the Opti.

 

[beldar boathead]

Does anyone know the size of the backer plate? If large enough, just turn the strap 180 degrees, put one screw in one original hole and the other in the new hole.

 

[mixmkr]

Just drill out the screw with a slightly smaller bit and run a tap carefully thru it, to remove the crud left in the old threads.

 

[L&VW]

8) Use a small hole saw, remove the center drill bit--use the broken stud as the guide. Remove the broken stud, fill the hole. (Tip from a DIY British boat site). Drilling out a broken stainless steel bolt....