JB Weld not holding

Try some CA glue it may hold better.

Also you can visit the web site called glue this to that for more suggestions

Hi Ron if you use JB WELD you have to use the one that takes 24 to cure the fast cure will not hold! there is a much better glue and you can purchase in Lowes Home Depot n target! oner of the best is gorilla super glue precise gel it will hold til the cows come hold repairs metal plastic wood shoes have not found anything it won't repair just let it dry overnight and then you can file cut shape whatever needs to be done! good luck my friend Ron! Alan

I'd look at the freshness of the glue - how long since it was opened?  Even if unopened before you used it, check the manufacture date.

Are the surfaces clean, and do they have enough "tooth" for a good bond?

I used JB to glue a caster that had fallen out of its welded socket. It didn’t work. After a bit I realized the glue didn’t have much to grasp. I engineered something to give it a larger surface area to grasp, and it worked.

I always used to use J B Quick. However, another very fast acting "fix" was Walthers Goo, and then add a drop of ACC once the item to be attacked is exactly in place. Something about the ACC instantly hardens the sticky Goo.

@Ron045 posted:

Did not know what the proper forum was to post this, so sorry if this is wrong.

I'm trying to use JB weld to mount a set of MTH horns (not sure what kind of metal).  To a brass base from an Atlas model.

It holds, but is very fragile and breaks off if gently touched.

What am I doing wrong?  Not mixing properly? Glue to old?  Something else?

I typically have great results with JB weld.

Should I be trying another glue method?

Thanks.

Ron

I have had great results with lock tight gel. But the real question is what does the break loot like and is it brass into plastic as well as has the hole been prepared?

I used JB-Kwik and have for years.  As long as there's something for it to grab, and it's not old, it's great.  Remember, JB-Weld (or JB-Kwik) need a roughened surface with "teeth" for a maximum strength joint.  I disagree that JB-Kwik give poor results, I've glued things with it and they're stood the test of time.  I filled the splintered wooden handles of some 40+ year old kitchen knives with it over ten years ago, they're still hanging in there, and they're used every day.

JB Kwik Vs. JB Weld | In-Depth Comparison

JB Weld is not always best for dissimilar materials. Likely what the horn is made of or plated with. A good CA may be a better alternative in that case. I am not a CA fan but found Gorilla CA to work well. Just takes a few minutes to firmly grab.

Pete

I have never found JB Weld (or any epoxy, I guess) to have a decent bond with styrene; I do not use epoxy on plastics much.

10 - 15 years ago I modified a K-Line MP-15 to give it fixed pilots (from styrene); I used epoxy to mount the assemblies. The next day I thought I had a "loose spot" and tried to fix it - but, all the styrene sub-assemblies (they were glued together using Testors cement) came off the existing metal loco pilot/epoxy mounts. Peeled right off.

So - the epoxy did provide a good, flat mounting surface for the styrene, naturally. It had been right there.

Walther's Goo solved the problem (as it so often does), and the styrene pilots/epoxy "mounts" are still on the loco. Goo is my "go to" for dissimilar materials - so long as it will be hidden (it's thick and ugly) and can get enough surface for a good purchase. It seems to get better with age.

I agree with Pete, if you’re trying to glue plated metals, ain’t no glue gonna have the strength to hold, ……the surface is just too slick,……personally, I like a mechanical attachment, even tiny horns like Ron’s working on, I’d drill into the base from the bottom, and start a couple threads for 2 mm screws….then glue can come out of the equation all together…..😉

Pat

I'm with Pat, if it's possible to tap them for screws, that's how I'd go.  I have some 1.4mm screws and the tap to match, they're perfect for attaching really small items.

If screws aren't possible, I'm a fan of Walthers Goo, messy to work with, but it sure does hold, even small items!

Try CA or Gorilla glue.  Use very small amount of latter.

@NYC 428 posted:

Try some CA glue it may hold better.

Also you can visit the web site called glue this to that for more suggestions

Thanks,

That site is great !

John

All,

Thank you for all of the replies and feedback.  I should have known better to provide some more back story.

I wanted a three chime horn but had great difficulty finding one with a rear base vs a bottom base.

So I thought I would just cut the base of the Atlas horn. This is the base from an AtlasO single chime horn.  I believe it's brass.

Then I purchased an MTH three chime horn that looked close to what I wanted and cut the bottom base off of it.  I believe it is/was plated.  This thing has been glued and cleaned so many times, I'm sure any plating was removed with the Dremel.

As mentioned, JB weld would hold it.  But just the slightest grab in the wrong area and it would break off.

I tried the Gorilla super glue some of you recommended because I had some available.  Rather than glueing the base directly below the center horn, I moved it in-between horn 1 and 2 to give it more glueing area.  So it's offset a little.  Not sure that falls in line with the prototype, but oh well.

Guess we'll see how this works.

Thanks again. For the help and support.

Ron

It looks good now, Ron, especially since it looks like you have been able to insert the pin on the horns into a hole beneath the cab roof. If the bond fails again, try removing the paint from just around the hole in the cab, inside and outside. JB Weld, compared to CA, doesn't like to bond to many paint films. It will bond securely to the ABS plastic the loco shell is molded from, however.

I dont know if this is what you want, but Bowser/Cal-scale sells a horn with brackets 190-3011. The horn isnt right (rear facing horn), but pick any horn from Cal-Scale, PSC, O Scale America, etc... and solder it to the bracket, then glue the bracket to the cab face.

I hope its good. But if it fails again, use a combination of Goo and Gorilla Super Glue Gel (GSCG)

Use a fresh tube of Goo.   Apply it with a toothpick to the horn base,  Don't gob it on, a small amount is better

Position it on the cab for just a second, then pull it away

Wait 2 minutes

Apply the GSGC with another toothpick to the cab.

Press the two together.  You have a few seconds to position the horn

Hold for 30 seconds, or better yet, apply CA accelerator

This will hold. I have used it hold kadee coupler pads to locomotives and rolling stock

I too have used JB Weld for decades.   In order for it to hold well, I have found that it needs surface area.   If you have a small part with little surface area to bond, then I have found it will only work well if you put a glob of it down, and then stick the part down in the glob. Not what you want for a model engine or car.

Also, the surface has to be absolutely dust, dirt and grease free. And the only way I have found to do this well is to use a degreasing product, such as the products used to degrease metal gun parts before rebluing.  Or, you can put on a mask and glove and wipe it with acetone.     But, for model train parts, these products are so harsh that they may strip off or discolor anything on the surface that is not pure metal.

These are just my experiences. 

Mannyrock

@Hot Water posted:

I always used to use J B Quick. However, another very fast acting "fix" was Walthers Goo, and then add a drop of ACC once the item to be attacked is exactly in place. Something about the ACC instantly hardens the sticky Goo.

Used the same method sir and it worked very well.

I found JB Weld needs to be put on generously and you can't squeeze the parts together too tight. Squeezing the parts together or clamping them squeezes out too much of the product leaving little to bond.