PIKO Fix vs UHU Glue

POLO_Train

Registered
10 Mar 2020
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Atlanta, GA, USA
I have a question for anyone else building PIKO and POLA buildings.

I have and had several 20-year-old POLA buildings where the plastic would break before the glue joints in those models. I perceive it as the glue back then was very strong because it was able to actually plastic weld the crazy plastic LGB and POLA was using at the time. I looked it up at one point and it was a crazy polymer compound that LGB used on its models. I didn't keep up with my hobby for years. 4 years ago I tried to kitbash a giant loco shed with a PIKO brewery kit and PIKO double loco shed where it spanned 5 PIKO building panels on the long side to fit a 24" engine with a shop at the end of it and I used the supplied UHU glue and bought more from the EU when I ran out of UHU glue. I clamped each section as well.

The problem is that the 5-panel section just fell apart under its own weight during transit when I was moving it to my new home. I feel I do not understand something that would cause those glue joints to fail so easily.

Any suggestions between UHU vs PIKO Fix?
 

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PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
27,331
2,819
Tamworth, Staffs.
The Piko product was obviously a solvent, which 'melted' (dissolved) the plastics, so it became one piece.
The UHU obviously does not dissolve the plastics, to anything like the same degree (if at all?) so relies on the 'stick' between glue and plastic. - Probably, glue and plastic expand/contract at different rates, so also (over time) weakening the joint.

My theory, anyway..
PhilP.
 

dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
18,608
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St.Neots Cambridgeshire UK
I found that UHU is a glue that is not much good for such purposes, the original stuff was a much better option quite likely from the days before the EU dumbed down many of the lotions and potions that we use in our modeling for us. However of late I have discovered a better option, UHU Power if you can source it. This is a good glue and thus far has survived outside very well. Though as ever I would suggest strengthening all external kit joints with External grade Silicone where it cannot be seen.
 

Rhinochugger

Retired Oik
27 Oct 2009
29,161
3,502
North West Norfolk
I've had stuff that has been glued with UHU outside for a few years now and it's still in place.

UHU is pretty good if used sensibly - there is also a solvent-free version of UHU which is a bit of a pain because it takes a long time to go off, but once it's gone, again it's pretty permanent :nod::nod:
 

penylanpip

Registered
1 Apr 2010
360
186
72
Barry, UK
www.gscalecentral.net
I have used "Ruderer L530" on repairs to LGB vehicles, also Pola, etc buildings with great success.

Bought mine from Amazon a few years back, but it is now only available from them with a stupid shipping charge.
No doubt your favourite search engine will come up with something more sensible. A tube should cost between £5-6.
 

Railway42

LGB, Radio Control Model Boat, Electronics
28 Feb 2013
426
48
Cheddar
I use Bison hard plastic adhesive glue super strong waterproof in 25ml tubes about £4
It is made to glue hard plastic, some of my buildings are 30 plus years old.
 

Rhinochugger

Retired Oik
27 Oct 2009
29,161
3,502
North West Norfolk
Yep, there is a Bostik glue designed for hard plastics - comes in a dark blue tube :nod::nod:
 

1to3

I'm New, Please Be Gentle
14 Sep 2015
62
7
The glue that comes in the box of Piko buildings is designed to be shelf stable. A store may buy a building and maybe they don't sell that one for 5 years. The included tube of glue still works... though it's not designed for outdoor use. (The instructions Piko puts in the boxes says not to use that tube of glue if you are using your buildings outdoors long term. Instructions suggest Piko Fix.)
Piko Fix is a glue that really only effectively lasts on a shelf for 1-2 years at most, so if the building you bought was on a shelf for 5 years before you found it... the Piko Fix would be way past its prime.
Piko Fix is about $10 or so and works great at welding/melding the seams and joints into one piece. That is what you want outdoors... you want the entire structure to fight nature together. So go over each seam 3-4 times and you should have a long-lasting building! (I have never had an issue at all... but I go over each seam on multiple sections at a time - then go back over each one 10-20 minutes later. If its a larger building, I will do this 4 times. After this much Fix, you will see the seam/joints are nicely rounded on the inside, and well molded together.)
 

POLO_Train

Registered
10 Mar 2020
17
0
37
Atlanta, GA, USA
The glue that comes in the box of Piko buildings is designed to be shelf stable. A store may buy a building and maybe they don't sell that one for 5 years. The included tube of glue still works... though it's not designed for outdoor use. (The instructions Piko puts in the boxes says not to use that tube of glue if you are using your buildings outdoors long term. Instructions suggest Piko Fix.)
Piko Fix is a glue that really only effectively lasts on a shelf for 1-2 years at most, so if the building you bought was on a shelf for 5 years before you found it... the Piko Fix would be way past its prime.
Piko Fix is about $10 or so and works great at welding/melding the seams and joints into one piece. That is what you want outdoors... you want the entire structure to fight nature together. So go over each seam 3-4 times and you should have a long-lasting building! (I have never had an issue at all... but I go over each seam on multiple sections at a time - then go back over each one 10-20 minutes later. If its a larger building, I will do this 4 times. After this much Fix, you will see the seam/joints are nicely rounded on the inside, and well molded together.)

Thanks! That is what I am hoping the PIKO fix will do and hold together, but I don’t feel it is welding the plastic together as testors did with plastic models. The PIKO UV resistant plastic is much more robust and would need more of a MEK to weld the pieces together?
I tried sanding down the surfaces to create the best contact and that definitely showed much better results with the PIKO fix.
 

phils2um

Phil S
11 Sep 2015
775
349
Ann Arbor, Michigan
I use Testors Cement for Plastic Models on Pola buildings and it works great. It does solvent weld the plastic Pola uses and is thick enough to have some minor gap filling properties. If the parts I'm glueing allow I'll put some glue on and rub the two pieces together along the joint line to make sure the glue is fully spread in the joint and properly "attacking" the plastic.
 

Fred Mills

Registered
27 Mar 2017
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Ottawa/Nepean, Ontario Canada
What is "Hard Plastic" ?
A great many structures put out by the hobby industry, and some rolling stock also, is "Styrene."
Most of the so-called glues are MEC based, or somewhat the same petroleum base as Lacquer Thinner, which works very well as a welding agent for Poli-Styrene.
Here in Canada I can purchase a quart of the lacquer thinner for about the same price I would pay for two ounces of the hobby "Glue" CS, or Crazy Glue works well too, but is way more expensive. Even acetone also is a solvent for Styrene.
These solvents should be used with caution…. They can work through capillary action at a joint, making "Welding" rather easy.
 

Fred Mills

Registered
27 Mar 2017
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472
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Ottawa/Nepean, Ontario Canada
I use Testors Cement for Plastic Models on Pola buildings and it works great. It does solvent weld the plastic Pola uses and is thick enough to have some minor gap filling properties. If the parts I'm glueing allow I'll put some glue on and rub the two pieces together along the joint line to make sure the glue is fully spread in the joint and properly "attacking" the plastic.
"Testers" so called "Cement" is basicly MEC/lacquer thinner, and a solvent for Styrene
 

phils2um

Phil S
11 Sep 2015
775
349
Ann Arbor, Michigan
Just to clarify a bit. UHU like 3M or MasterBond is a manufacturer of many types of adhesives. So you need to make sure you're using the correct UHU product for your particular application. Just saying "UHU" does not really tell anyone anything. For example, at this moment I'm looking at a bottle of UHU brand "All Purpose" adhesive. (edit added: It works great on cardboard.) But I'd never use it to glue polystyrene.
 
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dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
18,608
3,798
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St.Neots Cambridgeshire UK
Just to clarify a bit. UHU like 3M or MasterBond is a manufacturer of many types of adhesives. So you need to make sure you're using the correct UHU product for your particular application. Just saying "UHU" does not really tell anyone anything. For example, at this moment I'm looking at a bottle of UHU brand "All Purpose" adhesive. But I'd never use it to glue polystyrene.
I rather like the UHU Power for lots of jobs, about the only caveat on the label is that is is not suitable for Styrofoam.
 

POLO_Train

Registered
10 Mar 2020
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Atlanta, GA, USA
I feel I should help answer my own question on this topic. I began a simple test between all the glues I show above to see which is the strongest. I was fortunate to have the time to start building again, and I have many similar PIKO plastics trees left over to test on.

I am going to test on the Faller Exper, POLA G CEMENT, PIKO fix, UHU plast, and the UHU Allplast on the same plastic trees and see how they turn out. I am still very curious on this topic because my father's POLA buildings are rock solid to date and I bought many old POLA buildings where the walls broke before the glue did. I wish to test the glue I have bought and found in my recent PIKO and POLA kits.
I only have 4 machinest blocks right now. I will test each glue with one machinest block on top with the second supporting it so that it doesn't fall over during the day. So it will be a 5-6 day test, but I will let you know how it goes.

IMG_3345.jpeg
 

Fred Mills

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You might include testing the least expensive "Lacquer Thinner" in the test, as long as it is Poli-Styrene you are joining/welding together....
 

POLO_Train

Registered
10 Mar 2020
17
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Atlanta, GA, USA
I put the UHU plast, and the UHU Allplast through the gluing process, and now the POLA G CEMENT and PIKO fix through the same test. IMG_3361.jpeg

IMG_3362.jpeg

Sorry, I don't have the time to do the degreasing process of the second set of machinest blocks, but all are the same weight.

I have been using the PIKO fix to build all my PIKO buildings, but I am curious if there is a better glue for the job.
 

POLO_Train

Registered
10 Mar 2020
17
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37
Atlanta, GA, USA
If anyone is still curious, I found the POLA G glue to the strongest with an unscientific hand pull test. I let all of the them dry under the 1-2-3 blocks weight for at least 18+ hours.

The hardest to pull apart:
1: POLA G glue
2: Faller
3: Large UHU allplast
4: UHU plast (came in a PIKO box)
5: Small UHU allplast (came in a PIKO box)
6: PIKO Fix

I have been using PIKO fix for this build, but it broke away without much effort, as well as the small blue UHU allplast.
The small tube of UHU plast was a little more difficult, but I didn't break those plastic tabs.
The POLA G, Faller, and large UHU allplast I broke the tabs trying to pull them apart. The Faller and POLA was very uncomfortable to pull apart.

So I found that the big tubes should be the best for gluing together future baseplates and the buildings down onto them.

IMG_3372.jpeg