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Discussion Starter #1
I have searched and searched for an answer as to how to repair broken parts on an LGB product. There must be an adhesive product which will do that. I am posting this query on the TAP Plastics sponsored group in hopes that someone has had experience with one of their products. I don't see a product at TAP which will address this need. Perhaps I missed something.

I have had no success with any product other than J-B Weld which isn't what I would consider a desirable choice because of the gray "squeeze-out" line created when one presses the parts together. I was hoping for an answer to my needs in the April 2009 issue of Garden Railways (see page 68). But, alas, there was none! Maybe this topic will be covered in the next issue.

In the meantime, does anyone have the secret answer to this question?

Roger Bush

Fredericksburg TX
Fredericksburg, Mount Alamo and Southern
 

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Part of the probelm with LGB is the UV shiny finish.
I sandblast, grind, scrape before gluing.
To place people in seats, i drill holes and screw there butts into the seats. These stay where I put them with this method.
 

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I've had good success using super glue over the years. Just sand or scrape the surface on both parts and glue it together. Haven't had anything come off yet.
Just put them together with the glue on them and wipe them carefully then us accelerator.
 

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I learned a REALLY good trick with super glue from some guitarmakers: super glue (cryanocrylate) is ph-sensitive. It bonds much better to alkaline surfaces. On the parts you want to bond sprinkle a bit of baking soda-just a very light dusting.
 

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Since no adhesive that I've tried actually bonds to the engineering plastics that LGB uses, your best bet is to all a mechanical joint. This involves roughing up the surfaces to be bonded, as recommended by other posters, so that the adhesive has SOMETHING to wrap itself around. For weak joints, such as attaching figures, hot glue does well IF it goes on REALLY hot.

JB Weld is solvent based and if actually works, then find a way to deal with it's downsides.
 

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Discussion Starter #6
Thanks to all of you who replied. I did try CA glue but didn't achieve good results. That's probably because I didn't prepare the contact surfaces as y'all have suggested. I'll give this another try.

BTW, just what kind of material is LGB "plastic" anyway?


Roger Bush
Fredericksburg TX

Fredericksburg, Mount Alamo and Southern
 

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From what I can ascertain, LGB used many different plastics in their products. Many were "engineering" type plastics like Acetals (Delrin) and Nylons that are not glueable in the general sense. They are so slick and nonporous  that most glues tend to peel right off. That is why surface prep helps adhesion, but my experience has been that if you pull on the part the glued joint will still fail. There has been a lot of talk about the successful use of Cyanapoxy (or Cyanopoxy) on engineering plastics. Do a GOOGLE search and you can read many testimonials. The stuff is pretty pricey though. Some other types of plastics LGB used were "solvent weldable". These were types of ABS, Styrene and Polycarbonate (LEXAN). You can usually tell if the plastic you have is solvent weldable by putting a drop of MEK or another type of plastic cement on the plastic and see if it melts slightly. If done correctly, a solvent welded joint is as strong the rest of the plastic and will not easily fail when stressed.
Russ Miller
 

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What part and about what year was the model made?

Bodyparts- the OLD LGB stuff was BASF Luran S (has that LGB "smell") was used to the 1990s when they switched to BASF Ultraform (no smell). Both are automotive type plastics.

Reportedly, Technicoll 8008 is the best for this stuff, but I cannot find it in the US.

What I have used is Pola G Cement, 330592 or 3 (cannot remember for sure) with OK results.

Pure MEK works if you are willing to "melt" stuff to glue it.
 

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The variations of BASF Loran S are "ACRYLONITRILE STYRENE ACRYLATE", the oprative word we all recognize is STYRENE. This material is a BASF variation of ABS Plastic, that is why it melts and bonds with MEK. The BASF Ultrafoam is A "POLYOXMETHYLENE COPOLYMER" and this too is solvent weldable. Some of the plastics used by LGB, specifically in the detail parts, railings and trucks seem to be the engineering plastics that are not glueable.
The closest glue I can come up with for the Technicol 8008 Plastic Adhesive would be the IPS Weld-On #16.
Russ
 

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THe IPS stuff does contain Dichoromethane (MC) and MEK, while the 8008 is Acetone, Ethyl Acetate, Toluene, and 2-Butanone. The Pola/UHU stuff was Acetone and Butyl Acetate.
 

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Spule,
You are correct! I meant that the Weld-On #16 is the closest glue I can find in America that works on some of the LGB plastics. It is not the same formulation as 8008. The Acetone in the 8008 is in there as a general chemical solvent with a low flash point and is there to liquify the Ethyl Acetate. The 2-Butanone is MEK and that's what dissolves the ABS. The Toluene is in there for the Glue Sniffers and is not allowed in US formulations of glues anymore as far as I can figure. 29 years in the business and I've seen a lot of good chemicals disappear from the store shelves due to government regulations.
Have you tried the Weld-On #16?
Russ
 

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Russ:

Yup, brain fart, forgot that MEK = 2 Butanone, did not help that I was reading a German spec sheet on the 8008.

Actually, there are still industrial glues with Toluene here in the US. We also have many products with MC in them still around and in strange places. Yup, they get pulled by many companies (one large automaker removed it from all of its dealers recently), but we still have fatalities involving Methlylene Chloride in the US.

And yes, EPA has banned a lot of "good" stuff. Just ask my white grub population.....
 

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Discussion Starter #16
Just wanted y'all to know I have been following this thread closely. I have always had a generous supply of IPS Weld-On #16 on hand: but, that didn't work for me. I tried MEK - also have plenty of that around - didn't work. Made a brew of MEK, toluene and acetone (aka carburetor cleaner) which didn't work."'Crazy Glue" didn't work. Found something that did work! It's called Pasco Fix - see pascofix.com. Fixed all my waiting repairs successfully in just a few minutes. BTW, these were all small parts repairs. I scratched up the contact surfaces and cleaned them with carbon tet with each attempt of repair - I know - you aren't supposed to have this stuff but I have kept a supply around for many years. Best industrial solvent I've ever known.


So - just wanted y'all to know I found a solution.

Roger Bush

Fredericksburg TX
Fredericksburg, Mount Alamo and Southern
 

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Posted By SandyR on 03/30/2009 2:03 PM
Whichever of these solvents you use, for Pete's sake, use them outdoors!
SandyR


Why? Been using them indoors for years, just be smart about it.

I have been talking with the US agents for Uhu. Uhu Plast is stil made and sold in Europe, but they claim they cannot sell it here "due to MSDS regulations" whatever, in my many years working as an industrial hygienist, I have yet to hear this excuse!
 

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Found a post on another fourm I made years ago. The Pola glue that worked on LGB contained Acetone and n-Butyl Acetate as active ingredients and a binder/filler to make it thicker (methyl/nitrocellulose perhaps?)
 
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