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Which would be the strongest glue for this application

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  • Member since
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Which would be the strongest glue for this application
Posted by John-NYBW on Wednesday, February 16, 2022 4:52 PM

I am attempting a repair to the motor housing of a Walthers 135' turntable. One of the screws that was holding it down had the head break off. This has weakened the bond to the point where the housing won't hold the motor in place to where it will operate the gears. The motor assemble works if I clamp the housing in place but obviously that can't be done with a working turntable. My last resort solution is to try to hold the housing in place with a powerful adhesive, encasing it on all sides. If this doesn't work, the only other option would be to convert it to a manual TT.

I'm not positive but I think the TT bridge and motor housing are made of ABS plastic. If someone can confirm that it would be helpful.

I've found these two products on Amazon:

Amazon.com: Permatex 84145 Permapoxy Black Plastic Weld - 0.84 fl. oz. : Automotive

Amazon.com: J-B Weld 50139 Plastic Bonder Body Panel Adhesive and Gap Filler Syringe - Black - 25 ml : Industrial & Scientific

I'm also considering ordinary two part epoxy and since neatness doesn't count, Gorilla Glue. 

I likely only have one shot to get this right because if the adhesive doesn't hold the housing tightly in place, it's going to be difficult to redo it. 

Opinions wanted as to which of these would be the best option.  

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Posted by Tin Can II on Wednesday, February 16, 2022 5:08 PM

From my hobby shop days; i know that 2 part epoxy comes in several strengths, the longer drying time, the stronger the bond.  They also use fiberglass cloth to strengthen joints.  This is done by applying a layer of epoxy, laying the fiberglass cloth on the epoxy, and then coating/finishing with a top layer of epoxy.  Makes a very strong joint.  Not sure if this method would work for you, but if you can access the materials, might be worth a try.

 

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Posted by BroadwayLion on Wednesday, February 16, 2022 8:42 PM

But you said that the screw broke. Can you not then use a screw extraction tool, remove the screw, and then after gluing it you could then use a slightly larger screw.

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Posted by John-NYBW on Thursday, February 17, 2022 8:42 AM

I have several screw extractors but none are nearly small enough to remove the screw in question. If I could confirm this is ABS plastic, it would narrow the choices. I don't think it is styrene. It seems much harder than styrene. I've tried drilling holes into the side of bridge to hold the housing in place and the drill doesn't go easily through the plastic. That's why I don't think this is styrene. The side screws held on a while but eventually, the housing lifted out of place and the motor no longer turns the gears. That's why I need an extremely strong bond, probably a combination of well placed screws and the right adhesive. 

If there's a better option, I'm open to it. 

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Posted by rrebell on Thursday, February 17, 2022 10:01 AM

Micro mark sells a mini screw extractor set, but expencive. Might be able  to drill it out and bolt it.

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Posted by Overmod on Thursday, February 17, 2022 10:22 AM

Cut away two opposing sides of the 'post' with the broken screw shaft until you can grip the screw end with a pair of needle-nose pliers and start working it out -- file a couple of flats on the sides of the broken screw if you can't get enough bite to start it out.  Don't worry about messing up the plastic post: you can fill it up with a rod or some solvent-softened shavings and redrill for a new screw.  You could put a plug of JB-Weld in, file it flat, and drill (and tap if desired) for an applicable screw.  Unless you care about historic fabric for resale as a valuable collector's item on eBay (in which case I hope your retained the original box intact) this would be just as functional...

Same if you find the other screws have bent or hogged out as the result of operating with the one screw busted.  You may have to open up the holes in the plate or whatever slightly, so you can adjust the gear mesh and pinion tilt just right before dogging everything down.

I don't have one of these things, but I think it is right that they are some kind of ABS copolymer, perhaps with some polycarbonate (as in Lexan) added.  You might be able to confirm this with Walthers customer service directly.

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Posted by dstarr on Thursday, February 17, 2022 2:04 PM

A photo of the part would be helpful.  However, winging it, can you get the old screw out?  Then drill the hole clean thru, use a long screw, and a flat washer, lock washer and nut on the screw.  That ought to hold things together.  For that matter, you could drill new holes and put screws in them to beef up the joint. 

   I do not know of a reliable way to tell ABS from styrene.  ABS sneers at most adhesives.  There are a few special adhesives made for ABS but I don't know their names.  Try Loctite, they make a lot of effective stickums,

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Posted by NorthsideChi on Thursday, February 17, 2022 3:02 PM

Is this kit still made by walthers?  Wondering if they could send replacement parts since they are great about this.  Most plastic pieces they use will bond well with MEK based adhesives.  For really strong connections, I use plastruct weld cement (orange bottle). You may need to tape or clamp parts together for 10-15 minutes.  Avoid CA glues as the fumes can damage electronic components 

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Posted by John-NYBW on Thursday, February 17, 2022 4:09 PM

NorthsideChi

Is this kit still made by walthers?  Wondering if they could send replacement parts since they are great about this.  Most plastic pieces they use will bond well with MEK based adhesives.  For really strong connections, I use plastruct weld cement (orange bottle). You may need to tape or clamp parts together for 10-15 minutes.  Avoid CA glues as the fumes can damage electronic components 

 

This is the original non-DCC version of the TT. They no longer make that one and I don't know if they retooled the current version. The bridge and the housing would both need to be replaced. I've already heavily modifying it after the motherboard died. I removed the original electronics and have wired the motor directly to a variable power source. That has worked as long as the motor housing can be held tightly to the underside of the table. The slightest release in pressure causes the internal gears to slip and the TT won't rotate. 

I use Plastruct Weld for styrene but it is not nearly strong enough to hold this housing in place. It was the first thing I tried and it didn't hold for long. That's why I don't think this is made of styrene. I suspect it is ABS plastic which from my experience is much harder than styrene. It's going to require a very strong solvent and well placed screws to hold the housing tight enough for the motor to work properly. The screw that broke is unsalvagable. Any attempt to remove the stem is going to require tearing up the post and there will be nothing to screw into. I've attempted to hold the housing in place by drilling through the side of the bridge into the housing. That held for a while but eventually the pressure was too much. This is a last resort fix. If I can't find a strong enough adhesive to hold the housing tightly in place assisted by what ever screws I can drill into it, this TT is toast. A solvent that will fuse the sides of the housing to the sides of the bridge seems like it would be the best choice. I have three sides to work with, the side panels and the top of the housing to mate to the underside of the bridge. It's a matter of finding the right solvent. 

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Posted by selector on Thursday, February 17, 2022 6:23 PM

I didn't have your particular problem with that kit, but I had others that made it a real bust. The pit walls were not round.  The motor kit did not mesh with the pinion gear.  The wipers fell off the brass rings easily, so I had to fashion styrene flanges under both of them in case the wipers loosened and slid off.  Also, my bridge pivot never did fit into its 'bearing' cone very well, so I had to use a spacer between the pinion gear and the bridge floor....a great big dirty steel washer.  When I finally got it together so that the bridge could be mechanically/electronically swung, it would only swing maybe 190 degrees. So, I had to orient the pit so that the bridge would swing to the lead and thence to all three bays.

I recall having to wedge the motor on its back side, I think, so that it would mesh with the gear.  Is that possible for you, in which case you can save yourself the trouble and permanence of having to seal the motor in its casing?

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Posted by John-NYBW on Thursday, February 17, 2022 8:31 PM

selector

I recall having to wedge the motor on its back side, I think, so that it would mesh with the gear.  Is that possible for you, in which case you can save yourself the trouble and permanence of having to seal the motor in its casing?

 

The wedge is an interesting idea. I doubt it would take more than a thin piece of styrene placed on the underside to hold the motor in place. That might keep the motor in place even if the housing raises up. I might give that a try while deciding which adhesive will work the best. 

Just to update, I installed a wedge inside the motor housing and at first, it seemed to be working with just the screws holding it in place. The victory was a temporary one as have all the past fixes. They seem to work for a while, but I'm guessing there is so much pressure pushing the housing downward that in a short time, the gears had loosened. In this case, the fix was good for about ten minutes. It worked beautifully at first. By the time I got the power feeds to the bridge rewired, the gears were slipping and the TT was not rotating. I've got some JB Weld plastic bonder scheduled to arrive tomorrow. I'm going to give this piece of junk one last try. If a combination of JB Weld and ample screws are not enough to keep this thing operating, it's going the trash where it probably belongs. Life is too short to spend time trying to fix junk. 

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