Basing Glue Conundrum

[Firepower]

So this is a fun little hurdle that's been thrown up in front of me.  I've used Elmer's Wood Glue for basing for a good while, and it's been pretty dependable.  I formerly to use Elmer's basic white stuff, but was a trifle miffed with how one base wound up reacting to a bit of spilled water (hint: not well).

 

So I'm basing a bunch of boys at the moment.  The typical stuff, glue, sand, 24 hours, then a rigorous brushing to knock off the loose grains and chaff.  Yet suddenly, the sand is deciding to pop off in shingles.  Whole segments just snap right off.  One or two even formed solid disks that came off as a single piece.

 

Could the glue have just gone off?  I've never bothered to wonder if it has an expiration date.  

[Subtle Discord]

I'm not sure if white glue can 'spoil'. The glue may have settled, with more water collecting near the top and thinning the product. Or perhaps the base was slightly contaminated with something that impeded the bonding of the glue.

 

Broken record time.

 

If you don't want to ever need to deal with problems like this, I highly recommend an acrylic adhesive such as Perfect Paper Adhesive. Don't let the 'paper' in the name fool you, this stuff is amazing on many levels and not just for paper. Hands down, I completely swear by the stuff, this is the best adhesive I've ever used for basing miniatures. Thin, smooth, and not sticky when liquid so it spreads out easily, it shrinks and dries clear, tough, flexible, and waterproof. It is a little more expensive beside normal white glue, but a bottle will last for years with normal use and as a bonus, it works as an acrylic paint medium and a varnish for large-scale projects. Be sure to get the Matt variety because it does come in Gloss as well.

 

One of these days I'm going to do some articles showing this stuff in action and how it can be used for so many things. Seriously, you can water it down, paint it on cardboard so it can soak in, shape the cardboard, and when it dries the object will be rigid and plastic-like. Sand it, prime it, and you'd swear it was plastic.

[Firepower]

To be clear, the current issue is wood glue (the yellow stuff, very thick), not the white glue.  The stuff certainly isn't watery out of the bottle.  It's actually quite a pain to wrangle, with how thick and clingy it is.  Previously that's been fine, but this time it had the issues I mentioned.

 

So, next I tried thinning it first.  Same result.

 

I have a lot of models in my queue.  Having the very first step faltering is annoying, but having to wait 24 hours at a time to test whether it faltered is particularly frustrating.  

 

On a side note, I'm not sure I'd ever go through a 5 gallon bucket of adhesive.  I get buying in bulk, but when would you need 5 gallons of acrylic adhesive?*

 

If I can't find an immediate solution for the stuff I've got already, I might try to find that at my local art store.  I'm low on Medea airbrush cleaner so I'll need to make a trip soon anyway.

 

*Yes I know you can buy that stuff in bottles, but the tag line at the bottom of that ad made me giggle.

Edited February 25, 2018 by Firepower

[Arkhanist]

Wood glue can definitely expire - it may have a date on the bottle (it would in the UK). I think rated shelf life is like only a year, though you can get it to last a good number of years longer if it's stored in a cool dry place and not allowed to freeze or overheat (such as in a shed). The marker of it going off is basically it sticks to itself a lot better than to anything else, or comes out kinda stringy. If it's too thick to pour, that's also not a good sign! 

 

I've actually switched to matte medium for sand style of basing - it's basically non pigmented acrylic paint. Cheap and I already have a big bottle of it. Dries quickly, strong, waterproof, relatively thick but easily diluted. Bit of a secret weapon from model train scenery nerds.

 

"I get buying in bulk, but when would you need 5 gallons of acrylic adhesive?"

 

Someone who REALLY loves scrapbooking? Or more likely art schools and etsy factories...

Edited February 25, 2018 by Arkhanist

[Kinstryfe]

This may or may not help. When using loose basing materials, I've learned to always give it a coat of quite watered down glue (I use the white stuff) once the first glue below the materials has fully dried. It does add a lot of time (which is why I now tend to try to do bases in bulk), but usually seals the material pretty nicely and prevents pieces coming off. I sometimes also add pigment to get undercoating out of the way at the same time. May be worth trying, it sounds like maybe it just didn't form a good bond the first time.

[Subtle Discord]

I did a test with wood glue many years ago and I didn't like how easily it could peel away from bases. It's not guaranteed to fail by any means, but it dries very stiff and somewhat brittle and once it starts to peel it tends to come away in a large single piece. On a porous surface, it's excellent, but plastic just isn't what it's meant for.

 

Heh... yeah, 5 gallons is definitely overkill and for someone with some big projects. I only ever bought the 8oz. bottle which lasted the better part of ten years. It can do everything white glue can do, just better, really.

[Firepower]

I did a test with wood glue many years ago and I didn't like how easily it could peel away from bases. It's not guaranteed to fail by any means, but it dries very stiff and somewhat brittle and once it starts to peel it tends to come away in a large single piece. On a porous surface, it's excellent, but plastic just isn't what it's meant for.

 

 

That's pretty much what's happening now.  It's just odd that it only started happening after using it successfully for quite some time.

 

The stuff is thick.  Could very well have gone bad, so I'll check to see if there's a date on the bottle.

[Major_Gilbear]

Silly question, but have you tried roughing up the bases a little with some coarse sandpaper first? Also, have you tried washing the bases with detergent before using the glue?

 

If it worked before, and now it doesn't, it might not be the glue! ;)

 

Also, as for getting the stuff wet again... Try using the stuff that's waterproof once cured; you can still thin it and clean up with water and such whilst wet, but once it's cured and dry, it's set.

[Arkhanist]

Like paint, all adhesives bind better to a non glossy surface (more surface area to bond to) so it's always a good idea to clean off any release agent or oil as you would before priming a plastic model, and roughen it up a bit if possible. But given the wood glue is coming off in big solid chunks, I do suspect it's expired or getting close to it.

 

FWIW, after a bit of digging, I'm pretty sure PPA IS an acrylic matte medium, i.e. the same sort of acrylic polymer binder in water that makes up acrylic paints. It's about the same price as liquitex matte fluid medium which is a matte acrylic paint medium that doubles as a transparent paper collage adhesive and sealer.

 

PPA is transparent acrylic paper collage adhesive and sealer that doubles as an acrylic paint medium :)

 

So if you can't find PPA at your local art store, then you could substitute liquitex, golden or winsor and newton or the like artists acrylic matte medium and get the same results, just pick one with the consistency you prefer, it should all be very similar in effect. I much prefer it to wood glue, it's easier to handle and grips well.

 

Another thing you can do is prime the base aften cleaning but before adhesive. A good acrylic primer will bond very strongly to the surface of the plastic and provide a good layer for the next thing (thats its job, after all!) so will make whatever adhesive you end up using have a better bond between the sand and the base. You can then use another coat of primer after sand etc as usual to get the bond between the top of the sand and the rest of the paint job!

[Subtle Discord]

I can't provide hard information based on any actual testing, but based on my experience using PPA for 10+ years and having been a painter (both miniatures and visual arts) for even longer, Perfect Paper Adhesive and Acrylic Paint Medium are not interchangeable as an adhesive. Yes, with the way it's described PPA can be used in many ways that are the same as an acrylic medium meant for painting, but it is very different (read: much stronger) when being used as an adhesive. I have no idea what the additive/s might be that change its formulation but I highly doubt acrylic paint medium will perform as an adhesive the same way as PPA; why not just use acrylic paint to glue basing materials to a base in that case? It may come off as just a 'craft product' for collage and decoupage, but it's actually built up a reputation over many years for being a very good adhesive for a wide variety of materials like glass, metal, and plastic. I have no doubt the differences are likely small, but whatever it is, this stuff is absolutely adhesive first and paint additive second.

[Firepower]

I checked all my local hobby shops and no one carries the stuff.  Annoyingly, much the same story for medea airbrush cleaner barring a long trip out to an unpleasant part of St. Louis

 

So on to Amazon then.  Discord, this stuff works with sand, correct?  There's no mention of it in product descriptions or on the tin.

 

I checked my wood glue bottle and there's no printed expiration date.  So buying a new bottle would be a crap shoot on whether or not it's still good as well.

Edited February 26, 2018 by Firepower

[Subtle Discord]

Edit: If the glue has gone as thick as you suggest, it strongly suggests that it has at least evaporated some over time. Not sure how that might affect the bonding properties of the adhesive, but it does indicate that ti's likely getting old.

 

PPA doesn't seem like a particularly exotic product so it's strange for how hit-and-miss it can be to locate. I originally found it at al local Michaels Crafts store many years ago. When I finally went get a replacement bottle I had the hardest time finding it and thought it may be out of production, but naturally found it online.

 

I don't use sand in my basing personally, I used what I'm assuming is a milled nutshell or a similar product. Basically 'sand' that's produced by scenery companies like Woodland Scenics. With something like this milled product, the 'sand' will actually soak up some of the adhesive, making the bond extra strong. Seriously, I can scratch at the surface with my fingernail and the grains will just not let go. So, with that said, I feel confident that it will have no problem holding actual sand very firm given the surface properties of sand. The stuff bonds so many other things really well, I can't see why sand would be any different.

Edited February 26, 2018 by Subtle Discord