Touching up HO scale structures

[NILE]

I un-packed my model structures today and they are all in good condition after being put in storage for three years.  However, I notched that the glue/adhesive has yellowed.  What can I do to repair or cover this?

[Sierra Man]

Hello Nile, you could try to paint over it with a color that matches the surrounding area. Something that I have done is to make vines run up the sides or corners. This gives a great scenic effect. All it takes is a little white glue on a brush to make a line on the building then sprinkle on some ground foam. Have fun.

[Anonymous]

You could carefully weather them lightly, using weathering powders.

[galaxy]

Well, forgive me for saying this, but technically  no glue or adhesive should be showing anyway...that would indicate sloppy workmanship. but I think we are all capable of that. Glue will ooze.

~Also you can try carefully sanding it down {the glue} to minimize the appearance of it and remove some of the material before painting or weathering it or doing anything to minimize the aged glue appearances.

~If you paint over it, be sure to notate the color choices you made {including any mixture recipe} of paint you used to paint it and attach to the inside or bottom of the structure in case you need to repaint dings and such later {which shouldn't technically happen either, but often do.}.

As noted, Weathering may also work.

DO let us know how you solved your problems as I am sure others would like to know,  as dried glue can be a hassle when it ages and such.

 

[doctorwayne]

Galaxy is correct:  there shouldn't be any glue showing.  I'm wondering what kind of glue you used to have it show and to be yellowing.

For styrene plastic, the best "glue" is a liquid solvent-type cement, such as offered by Testors.  I use ordinary lacquer thinner with good results, as it's a lot cheaper and is useful for lots of other things.  I buy it by the gallon and decant it into smaller cans for airbrush and brush cleaning, thinner for lacquer-based paints, and into sealable glass or metal containers for stripping paint from metal models.  An empty and cleaned paint jar or a Testors liquid cement bottle with the brush-in-cap makes good container for it when using it as solvent cement.  Use either the brush-in-cap or a suitably-sized paint brush to apply it.  Depending on the type of joint being made, you can apply it to one or both surfaces to be joined, or fit the parts together and apply the cement to the joint - it'll be drawn into the joint by capillary action.  This type of cement dries quickly, allowing you to work almost as quickly as you wish, but to get full strength in a joint usually takes a little longer.  For parts which don't fit well, use a knife or file to improve the fit, and, if necessary, clamp the joined parts overnight to allow the bond to fully harden.  If you get solvent cement on visible surfaces, don't attempt to wipe it off, as it will further mar the finish.  Instead, simply let it evapourate - it will be much less noticeable.
Most plastic structures benefit from being painted, so your yellowed glue can be covered with a coat of paint, either matching the colour of the structure or painting the entire structure a different colour - an easy way to individualise your models.  For localised problem areas, the suggestion of applying vines works well.

For new construction, I like to assemble the basic structure (walls, floor, roof) then paint these, either as sub-assemblies or as a complete structure "shell".  This way, any minor solvent damage is completely covered, and all joints should become invisible.  You can paint the details (doors, windows, trim, etc.) while they're still on the sprues, either masking-off the attachment points or scraping the paint from them afterwards, as paint will interfere with the working of the solvent cement.

Wayne

[galaxy]

TA462

galaxy

Well, forgive me for saying this, but technically  no glue or adhesive should be showing anyway...that would indicate sloppy workmanship. but I think we are all capable of that. Glue will ooze.

 

Glue will ooze if you've used way to much.   A lot of people only use one type of glue to build kits.   Great model builders use different types depending on the project.   Sure we can all be capable of it but some choose not to.  It comes with years of practice and trial and error.  My glue doesn't ooze. 

I was giving the guy some credit.

But, it sounds to me like you are calling the OP a worthless crappy modeler by inferring that he is not a "great model builder" and that he is not among those who are skilled by saying "some choose not to".  I'll bet he thanks you for THAT opinion.

[BRAKIE]

doctorwayne

For styrene plastic, the best "glue" is a liquid solvent-type cement, such as offered by Testors

Wayne,I've tried several liquid glues and never had any luck.

So,what works best for me is Testors tube glue applied with a tooth pick..

[secondhandmodeler]

BRAKIE

 

Wayne,I've tried several liquid glues and never had any luck.

So,what works best for me is Testors tube glue applied with a tooth pick..

I've had similar results as Larry.  The liquid glues don't seem to hold very well, at least they didn't for me.  I continue to use old school hobby glue with okay results.  Just don't look too closely!

[doctorwayne]

The liquid glues work best if the parts fit together well, and a properly-made bond is pretty-well indestructible - the material near the joint usually will break before the joint will (if you're trying to dismantle something). 
The main working ingredient in tube glues meant for plastic is a solvent of some sort, such as toluene or methyl ethyl ketone, the same stuff that's in lacquer thinner, and the rest is a filler (which is why the joints are usually weaker).   You can make a filler-type cement by dissolving styrene plastic in a jar of lacquer thinner, but it's not as easily applied as squeezing stuff out of a tube.  I've used it occasionally as a filler on styrene where it would be otherwise difficult to get a good fit.
Lacquer thinner (and commercially-available solvent cements for styrene) don't work on all types of plastic, so they're useless for gluing anything such as Celcon, Delrin, or other engineering plastics.

As for set-up times for joints made using lacquer thinner, it will vary depending on what's being assembled.  If you're putting together a basic structure, you'll have plenty of time to ensure that everything is square and perpendicular, but unless the structure is very small, you won't be able to handle it until the joints are hardened.  If those four walls are built on a base, like many Walthers kits, there's less chance of it skewing under handling, so even if the joints aren't fully hardened, it's unlikely to fall apart if handled carefully.  For models which don't fit together well, you'll need some method of holding things in alignment while the bond cures, usually overnight, before handling it or removing the clamps.  Elastic bands work well, but remember to insert spacers (two at each corner) to prevent the elastic from touching the joint, and drawing solvent onto the visible surfaces.  The elastic may become attached to the plastic or simply dissolve.
If you're attaching styrene details to a styrene model, you should be able to work continuously without waiting for the joints to fully harden, especially if there's also a mechanical joint involved.   Any joint which would be subject to stress during handling needs to be allowed sufficient drying time:  if you cement a smokestack to the roof of a factory, then place it on the layout, it'll be fine unless your layout is subject to high winds.  If you install the smokestack, then flip the building over on its side to install doors and windows, the smokestack will likely fall off.

If you dislike using fillers and body putty, it's well worth the time and effort to create good-fitting joints.  Shown below is the end of an old Rivarossi stock car.  I bought two of them at a train show many years ago.  I later learned that, while they were fairly accurate models (for their time), the bodies were about a foot too wide.  The usual method for dealing with this is to insert a tight-fitting block of wood into the body shell, then run it lengthwise through a table saw.  Unfortunately, I neither own a table saw nor know anyone who does.  Instead, I did the cutting using a hand saw (szrooba, szrooba) then used a 1/2" brush to apply a liberal amount of lacquer thinner to both mating surfaces.  After waiting several seconds for the plastic to soften, the mating halves were squeezed together and clamped with elastics.  The next day, the elastics were removed and any excess material was easily scraped away using an X-Acto #17 chisel blade, then the car was painted and put into service.  You can still see the joint in this enlarged photo, but it's certainly not noticeable on the layout or under close inspection.

Wayne

[BRAKIE]

Wayne,I'm well aware of the need for good joints etc,etc but,still l had have terrible luck with bottle glue including Testors so,I stayed true to the method I learned way back in the early 60s when I first started building Revell kits with Testors tube glue...

I still use Walthers GOO the way I was taught by my Dad..It bonds things forever and a day.

[doctorwayne]

I think that everyone has a preferred method of putting things together, but as mentioned earlier, it's good to be aware of what's available, as there's no one glue that's the best for everything.

Years ago, after seeing so many references to GOO, I bought a tube, used it once and threw away the remainder, then went back to my favourite at the time: Pliobond.  Just recently, I was working on a locomotive for a friend and discovered that he had used GOO to secure a large lead weight to the inside of a Bachmann tender.  It was cemented to the underside of the tender's deck and the deck was severely warped, with large cracks where the GOO had been applied.   I still like contact cement for a lot of applications, but prefer the gelled variety from LePages or Weldbond.  It's very good at joining wide expanses of material, similar or not, and is useful for preventing steam loco siderod and valve gear screws from backing out due to the motion of the moving parts.  Apply a small amount to the endmost threads of the screw, allow it to dry for 20-30 minutes, then screw it in place.  The slightly sticky residue provides enough of an interference fit to hold the screw in place, yet still allows easy removal when necessary.  It'll do the same thing for Kadee knuckle springs if yours are always popping out - I have some which were thus treated over 50 years ago.

For styrene, I haven't found anything as effective, easy-to-use, or as cheap as lacquer thinner.

Ca is useful for joining many dissimilar materials, but benefits greatly from also having a mechanical connection:  either interlocking surfaces or holes into which parts can be inserted before the ca is applied.

Epoxy is also useful for dissimilar materials, especially where the fit between parts being joined is poor.  Like ca, its usefulness is improved by mechanical connections.

I don't work much with wood in modelling nowadays, but used mostly white or yellow glues.  Nowadays, I'd use contact cement instead, although it's best suited to large contact areas.

Wayne

[icguy]

 

You could use Methyl Ethyl Ketone available at Menards and other box stores.  Works well on most styrene and maybe other plastics to.  One can of it can be a lifetime supply of used sparingly.  Also would be a good idea to use it in a well ventilated area away from pilot lights.  A little safety and some common sense.  I think its a lot better than Testors.  Just my opinion.

[NP2626]

I use Testors liquid and have had no problems with things falling apart.  I find that just picking up a tube of Testors; or, other types of tube plastic cements causes the cement to ooze from the tube and I think it's because my hands are always warmer then the glue and causes the cement to expand .  This makes getting a small amount of the tube glue where it needs to go without globs of the stuff coming out difficult! So, I only use the tube plastic cements where the excess glue will not be seen.