Screw doesn't hold in Top Bow

[rainer]

Hello.

I have a Two Man Top on my Touring '16. While everything looks good from outside, also the top is sitting well, I permanently have issues with two screws at 2nd bow (at rear seat). I am talking of the screws holding the top in place, approx. 1-1/2" before the end of metal part. This screws always get out of their hole and I cannot tighten them well.

I already tried to drill up the brass washer a little bit and use a thicker brass screw because the hole was worn out so much, but this didn't help. The pipes also appear to be either very thin-walled or rusted from inside, because it was very easy to cause a little dent around the screw hole.

How deep is the wooden bow normally reaching into the pipe? I guess it should be more than 2"? In this case, the screw should sit in the wood, too.

My idea is:
If the metal pipe is/was very rusty and therefore so easily to dent around the screw hole, it will already require to be armed. I could try to squeeze Epoxy, mixed with thickener, though the screw hole, using a syringe without needle. In other words, fill the hole behind the screw hole with something getting very hard to give the screw something to sit in. If the bow isn't reaching over the screw hole, this will become more difficult, but still possible, by repeating this a few times. After the Epoxy has hardened, I can drill a new hole for the screw. As the resin will soak into the rust, this will also arm the thin-walled pipe.

I think this Epoxy method is one of very rare options at all.

Any ideas on how to fix this?

Rainer

[A Whiteman]

Sounds an option.

Maybe try putting a hard wood plug in the hole, then screwing again. A small plug often gives enough bite for a screw to purchase on. This will only work if there still is wood in there, else your epoxy idea may be the better short term quick fix.

[jsaylor]

I have had good luck driving round tooth picks, dipped in wood glue into old holes. When dry cut off flush.

[CudaMan]

What jsaylor said. Here is the technique used on my 1912 Flanders 20.

[Rich Eagle]

Those irons are usually double walled. Condensation works in and the two walls plus the wood let it stay wet and rust things. More so as the water runs down. The upper part is likely less rusted than the lower part. You might want to see if there is any rust coming through at the lower parts before you do much else. They are the weakest where the sheet metal tubes are brazed or welded to the bottom stubs. Many have restored bows that looked good on the outside only to have them collapse later because of rust. I hope that isn't the case with yours but examining them could save some problems.

Mine had wood filler pieces between the bow end and nearly to the bottom. The bows go into the sockets about 4 to 6 inches I believe.
Toothpicks and/or epoxy should work well. Try to get as much inside as possible.
Let us know how it works.
Rich

[Erik Johnson]

Are you talking about the screw that holds the leather strap and key/pin on the top socket?

Here is a photo of my 1917 roadster top sockets that I recycled from another post (the reason for the arrows). The top most arrow points at the leather strap to which I am referring.

Be aware that the original, factory screws are squared-off just under the screw head. This keeps the screw from spinning around in the leather strap and subsequently prevents the screw from backing out of the top socket and, ultimately, prevents the loss of the screw even if the hole in the socket or screw threads are stripped.

[jiminbartow]

An old woodworking trick is to use wooden golf tees. They are great because they are tapered and can be driven in tight. If the tee has a varnish finish, run sandpaper over it so it it bare and roughed up (so the glue will adhere to it). If the hole is rather big, then cut the pointed end off so the taper of the tee will fit tight in the hole. Fill the hole with Tightbond wood glue and drive in the golf tee so it is tight, but not so tight as to split the wood. Let it set a couple of days, cut off the head of the tee and redrill the hole to the proper size of the screw. Jim Patrick

BB599049-9AE8-4103-89E6-EDA103B61263.jpeg (17.78 KiB) Viewed 1697 times

[rainer]

The holes are not so big as you possibly imagine, only big enough to let the screw get out when the top is flattering in the wind.
But the metal tube is very weak (at least around the screw hole), so forcing something into it will most probably only widen it without increasing ruggedness.

I will try the Epoxy method. This will result in a hard block inside, sticking to everything around the hole.


This way I finished a garage window (wooden window, never painted over 30-40 years. The wood soaked up 300g of Epoxy! now it is rock solid again, I sanded and painted it, the window is like new. I expect the same from squeezing Epoxy into the hole.

[Rich Eagle]

Just two more thoughts, you asked how far the wood goes down into the bows. Here are my new '14 bows.

Also, I noticed that sometimes many holes were made for the tacks or nails in the area I believe we are talking about.

I wasn't exactly sure where the Hole you mentioned was located but assumed it was at the top of the iron. If so, maybe simply relocating it would make it more solid.
Rich