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Thu Oct 10, 2024 10:48 am

Jacks wrote: wagen19 wrote: Martin Southwell wrote: Fine, but not everybody has welding equipment or experience.

You can do it with a profi and sometimes save a lot of time. (imo, johnshenry x2) What is a profi?

Sorry, "profi" is german for "professional".

Fri Oct 11, 2024 12:43 am

Everyone tinkering with old cars should at least have a small welder at home. Entry level flux core welders are cheap and can be very useful at home. Practicing on scrap metal will make you get the hang of it very quickly.

Mon Oct 28, 2024 6:04 pm

scarabee wrote: Everyone tinkering with old cars should at least have a small welder at home. Entry level flux core welders are cheap and can be very useful at home. Practicing on scrap metal will make you get the hang of it very quickly.

I'll agree except don't waste your time on flux core welders. Even their best welds are crappy. I took the bait and years later bought an entry level Lincoln 120 volt MIG welder with C25 bottle. Wished I hadn't wasted those years with a flux core welder.

Tue Sep 02, 2025 6:42 pm

Here's something a bit out of my area of expertise and some really cool thing I figured out. One of those things that you turn over in your head for days, then think "I'm just going to try it today".

One of my good friends in the hobby gave me an NOS Vert smooth sem that had a bent arm and a warped lens to try and fix. The arm was a piece of cake. The lens I fiddle with a bit, then tried to clamp a "mold" inside it and put it in a little oven in my shop at around 200F.

Within a few minutes the lens was completely trashed. Yes, the rare "Orange Juice" colored, vert only lens.

I panicked for a bit, then reached out to a well known semaphore restorer in Canada. He had 5 of them, one NOS or near to it, and 4 others that were badly warped. He sold me the NOS one and gave me the other 4. I told that I'd try to straighten them.

The problem with these lenses, is that over time, they warp, and shrink. In original shape, the top edges of the lens should be slightly convex. When they warp, they go concave at the top edge, and the overall length shrinks by as much as 1/4". Installed in the sem, ugly gaps are seen.

Here is a pic of a warped one in the sem:

A gap is seen between the arm and sem lens.

You can see this with the lens on a flat surface:

So I had this idea to make a wooden "buck" for the lens and then soften it by putting in boiling water. Made from a very hard Poplar wood, it was a bit less than 2 hours with a scroll saw and Dremel to make this thing:

With a lens on the tool, I made a mark in the wood at the back edge of the NOS lens. In this pic, a "shrunk" lens is used, and you can see that it comes up well short of the mark.

Looking at the top edge of the lens, you can see that it doesn't follow the contour of the top surface of the tool which was carefully sanded to match the curve of the NOS lens.

Here is a pic of the NOS lens on the tool. The top edge of the lens matches the contour of the tool, and the back end of it meets the reference mark:

Here is lens in the boiling water. I use a mini "Fry Baby" deep fryer, and prior to stretching the lens, I immerse all of in the boiling water EXCEPT for the very back end where the screw hole is.

And here's the really cool trick (I am really surprised this really worked, and proud of myself for coming up with it!). There is a hole drilled in the wooden tool right where the screw hole in the lens is. In the shrunken lens case, the holes don't line up. But using an awl (after boiling the lens for about 15 seconds), I could grab the lens hole with the awl, and apply pressure and pull the end of the lens, stretching it. It worked perfectly. The fact that the bolt hole area of the lens was left out of the boiling water insures that the lens doesn't stretch there, or distort the bolt hole in the lens.

After stretching, the back end of the lens reaches the reference mark:

Next, is the warping. A 2 handed operation while plastic is hot, so no cell phone pic. But I dunk the lens again for 15 seconds or so in the boiling water, then wrap it in a towel, both thumbs in the underneath center of the lens, and push up and hold. After a few seconds holding that, I dunk the lens in a container of cool water.

Here you can see it follows the contour of the tools top surface a little better:

Repeat. Now even better:

This lens has a small crack near its nose end (Always use your WORST part when trying some now modification/repair). But it now matches the tool dimensions perfectly.

Back in the sem with no ugly gaps!

One thing I did find was that after a few hot water dunks, the wooden tool started to swell but, pushing the sides of the lens out. Have to let it dry out a bit before using it again. I use a wood moisture tester and when it get back below 6% or so, I can use it again.

Tue Sep 02, 2025 7:55 pm

Very impressive (+ didactic as usual JH, Thanks for imparting your insights and considerable expertise!
I've wondered what sort of black magic or druidic incantations you deployed in returning my '52 semaphore to pristine condition?
You sir, are truly the "dojo of semaphore esoterica...and I remain endebted to you for certain!

Wed Sep 03, 2025 8:53 am

Bravo!! =D>

Wed Sep 03, 2025 8:59 am

=D> =D> =D> =D>

Thu Sep 04, 2025 5:49 am

Awesome John! :thumbsup: :thumbsup: