Wood Glues

[CLovehitch]

Anybody know how often to replace wood glues?

Any clear transparent good glues? Weld bond?

Thank you in advance for your help!

Nick

[Hsae]

I am using Titebond, according to the manufacturer it is good for 1 year, but I had an open bottle for over 1 year and it was still good.Titebond quick & thick dries clear.

[Bob Cleek]

In terms of shelf life? Obviously, it depends on the type of glue. As for modeling glue, PVA will let you know it's past its expiration date when it gets thick, if not hard, in the bottle. Epoxy doesn't seem to have a expiration date as long as its containers are kept tightly sealed. CA adhesive will last practically forever if you keep it tightly capped in a sealed zip-loc plastic bag in your freezer between uses. Shellac will last forever and can be reconstituted by adding additional alcohol to the mix. As for the rest, which aren't particularly advisable for use in ship modeling, see: Wood glue - Wikipedia and read the instructions on the containers.

 

The only perfectly clear glues used in modeling that I know of are CA and Duco, a nitro-cellulose glue formerly popular for styrene model assembly and balsa model airplane construction. PVA (e.g. Titebond) will dry without color, but is somewhat cloudy and not perfectly clear, although when used to create properly formed joints, PVA should not be visible at all. (Some actually add black color to PVA in order to accentuate the joint lines in decks and timbers in bright-finished models.) As for which are "good" and "clear," I would say Titebond PVA in any of its permutations is about as good a wood glue for modeling as is available these days. Epoxy and CA have their place in joining dissimilar materials, particularly wood and metal. Beyond that, most "modern" adhesives pose risks associated with out-gassing and less than optimum archival qualities. See: Nautical Research Guild - Article - Specifications for Construction of Exhibition Models of U.S. Naval Vessels (thenrg.org) and Nautical Research Guild - Article - Ephemeral Materials in Ship Models (thenrg.org) for detailed discussions of materials to be used in ship modeling.

 

 

 

 

Edited February 24, 2023 by Bob Cleek

[Jaager]

Weldbond is just another brand of white PVA.  It dries clear - just as any other white PVA does.  Whoever does their writing for the directions has a real talent for misdirection.  From reading it, it casts the product as being somehow unique.

 

The yellow versions of PVA dry transparent, but with an amber tint.

For Titebond - it seems that the price / ml is half at the next volume.  The gal is way less per ml than the 4 oz.  If you were in a large club and bought a gal and then divided it up into 4 oz portions spread over the membership, there is a deal - probably not cost effective, but a deal on paper.   This is probably one of those situations where buying a 4 oz bottle and getting a new one as needed actually is cost effective.  Especially if your interest waxes and wains.  Then too, there are stages that are glue heavy and others where not much is needed.

 

 

[Dr PR]

I have been using Duco Cement or similar glues for at nearly 70 years and it keeps forever. It contains acetone and other volatile chemicals, so if you live in California you should worry that it will cause your ears to fall off. I know it isn't "fashionable" these days, but it works very well with wood. It does dry clear, but it leaves a visible film. It sets up in about 20 seconds but doesn't form a strong bond for about an hour. It hardens fully in 24 hours.

 

I have used PVA and it works, but I end up throwing most of it out because it hardens in the bottle, even when kept capped.

 

I never use CA (cyanoacrilate). It turns to rock in the tubes before I get around to using it. If I do get to use it the necks of the tubes clog after a single use.

[Bob Cleek]

5 hours ago, Dr PR said:

I have been using Duco Cement or similar glues for at nearly 70 years and it keeps forever. It contains acetone and other volatile chemicals, so if you live in California you should worry that it will cause your ears to fall off. I know it isn't "fashionable" these days, but it works very well with wood. It does dry clear, but it leaves a visible film.

I have to confess I've used Duco Cement almost as long as you  and I still do, perhaps because I'm used to it. Because I try to the greatest extent possible to create a mechanical connection when joining fittings and parts, I find it is much easier to work with than epoxies when gluing a metal mounting peg into a wooden hole. Duco is nitrocellulose  that's been dissolved in acetone, so a lot of people in California get their knickers in a knot over it, but so far it's still available in most hardware stores. A homebrewed approximation of Duco Cement can easily be prepared, athough with a styrene base instead of nitrocellulose, by dissolving styrofoam packing material in acetone until a sufficiently thick consistency is achieved. It takes a surprising amount of styrofoam to accomplish this, but i always seem to have plenty of the stuff on hand. Both nitrocellulose and styrene are probably not very archival, but when used to cement pegs in holes, they seem to do fine. 

Edited February 24, 2023 by Bob Cleek

[Roger Pellett]

I use Duco Cement to temporarily laminate brass sheet to craft plywood before passing it through my Byrnes saw to cut strips.

[Dr PR]

I have one wooden POB model ship that is 53 years old that was glued together with Duco cement (or a similar wood glue from the 1960s) and it is still holding together with no problems.

 

Nitrocellulose has been used in wood finishes on guitars and finishes for metal musical instruments for more than a century. It was also used for photographic film.

 

Of course guncotton is nitrocellulose, and it is used for rifle powder and used to be used for the powder charge in large naval guns. So don't set your model on fire or expose it to a strong shock or the nitrocellulose might explode!

[Snug Harbor Johnny]

5 hours ago, Dr PR said:

I have one wooden POB model ship that is 53 years old that was glued together with Duco cement (or a similar wood glue from the 1960s) and it is still holding together with no problems.

 

Nitrocellulose has been used in wood finishes on guitars and finishes for metal musical instruments for more than a century. It was also used for photographic film.

 

Of course guncotton is nitrocellulose, and it is used for rifle powder and used to be used for the powder charge in large naval guns. So don't set your model on fire or expose it to a strong shock or the nitrocellulose might explode!

  Per the History Channel, late in the 19th century they tried using nitrocellulose as a substitute for ivory billiard balls.  There were pool games that had explosive results when the impact from the cue ball was too great !  

[Roger Pellett]

My father graduated from the University of Cincinnati in 1932 with a degree in Aeronautical Engineering.  At the height of the depression he and my mother decided to supplement their income by selling model airplane kits designed by my father.  I still have sales literature for their short lived “Viking Aircraft Company.”

 

A part of this enterprise involved manufacture of “Duco type” cement that was included in the kits.  My father described this as dissolving Celluloid plastic in acetone.  This activity took place in the basement of their rented house in the vicinity of the open flame water heater.  The landlord eventually put them out of business.

 

Roger

[Jaager]

I have found Duco to be unreliable where there is significant shear force and the surface area of the bond is equal or less than the surface area where the force is applied.

 

There is always the glue used before synthetic chemistry became involved:  hide glues.

[Bob Cleek]

1 hour ago, Jaager said:

I have found Duco to be unreliable where there is significant shear force and the surface area of the bond is equal or less than the surface area where the force is applied.

Very true! For this reason, mechanical fastenings are to be preferred in all instances. 

 

I've found the same to be true of every other adhesive I've ever encountered. I've discovered through empirical analysis as well that the incidence of unreliability increases in direct proportion to the increase in shear force applied, regardless of the ratio between the surface area to which the shear force is applied and the surface area of the bond. 

 

I believe this is known in physics as the "bigger hammer principle." 

 

   

Edited February 25, 2023 by Bob Cleek

[Jaager]

43 minutes ago, Bob Cleek said:

I've discovered through empirical analysis as well that the incidence of unreliability increases in direct proportion to the increase in shear force applied,

With what I do, the major force is perpendicular to the plane of the bond:  sort of like feeding the edge of a piece of plywood against sanding drum or disk - or exactly that.  But there is enough collateral tangential force that Duco is a failure.

[Bob Cleek]

I find Duco useful sometimes for gluing metal pegs into wooden holes. That's about it. 

 

[Jaager]

It works to fix toothpick handles into small blocks of packing foam to make a glue spreader.  It resists the water in PVA and tap water to clean the spreader.

[JohnLea]

On 2/23/2023 at 7:55 PM, Bob Cleek said:

In terms of shelf life? Obviously,

 

 

Again, this Cleek guy knows stuff.

[Bob Cleek]

2 hours ago, JohnLea said:

Again, this Cleek guy knows stuff.

I've lost count of how many half-full bottles and tubes of hardened glue I've thrown out.  

[Robere210]

I've done a lot of precise and not-so-precise woodwork over the years.  My favorite now is Gorilla Type II wood glue--not the foaming urethane glue.  However its not best for structural gluing, where the pieces are under constant tension.  For anything under constant tension I used to use Weldwood plastic resin glue--it is a powder that you mix with water.  But I believe the gub'mint declared it verboten, cause I haven't been able to find it.

[jdowney]

Has anyone tried hide glue?  I use it on furniture sometimes, usually if I'm making something nice that I want to be repairable.

 

I used to use Duco and Ambroid on balsa airplanes.... Good all around glues.

[Jaager]

I used Franklin pre-mixed Hide glue as a reversible glue.   It holds too well the way I applied it.

I coated both surfaces.  I used tolerances that were too exact.

Hide glue is a protein.  Hot ethanol will denature it and have it curl into small balls.  It would have been exactly what I want - if there was room for the hot ethanol to penetrate the glue joint.

 

Hide glue is probably what the pre- 20th century models were assembled with.   If your goal is a 100-200 year lifespan it should serve.

The Franklin and Old Brown versions are convenient but the high percentage that is water is a worry.

The glue pot hot dissolved flakes has much less water and would probably be the wise option.  Offering a wide choice of critter origins for relative strength.

It is however a witches brew process that takes addition time and skill before the actual wood joining step can begin.  This lack of convenience is a difficult hurdle to justify when compared to just applying a bleb of Titebond II spreading it as a complete monolayer on both meeting surfaces.

 

About Duco -  it probably helps to read the directions.  Totally coat both meeting areas - let dry - apply a wet layer and get together really sorta fast.  It does hold better.

Edited February 28 by Jaager

[Dr PR]

I have had little trouble with Duco (nitrocellulose in acetone) type glues on models. There are not many stresses involved if the parts are shaped correctly.

 

However, I have seen two types of failures:

 

1. With soft wood (balsa) I have seen broken joints where the glue adhered well to one side and the wood broke away from the glue on the other side. This left the glue with bits of wood embedded in it.

 

2. I used to plank hulls (single layer planking) by applying glue along the edge of the plank being installed - to join with the neighboring plank edge - and to the bulkheads. I have never seen a plank break away from the bulkheads, but because of swelling and shrinking of the planks due to temperature and humidity changes gaps have appeared between planks, even on painted hulls.

 

The best solution I have found to this problem is to paint the entire interior surface of the planking with thin epoxy paint, also covering the join between planks and bulkheads. The epoxy soaks into the wood creating a tight bond between all pieces. I have been doing this for about 40 years and have never seen a crack develop between planks on single layer planking.

[Roger Pellett]

Building ship models can involve solving such a wide rage of problems that it really depends on what you’re trying to do.  

 

For gluing wood to wood commonly available PVA glue; the yellow stuff.  Elmer’s, Titebond, both work fine. Possibly other brands too.  IMHO, it’s all the same stuff.  Requires clamping pressure.

 

Special gluing problems like lightly loaded or interlocking metal to wood joints: Nitrocellulose based glue. Nitrocellulose based clear fingernail polish works great.  It also works for wood-wood joints where clamping pressure cannot be applied.  Duco is its the same stuff, just thicker.

 

For larger wood metal joints, Epoxy.  I especially like JB Weld, it’s easy to squeeze out a couple of blobs and mix.  Eyeball can judge 1:1 proportions.

 

CA Glues:  Don’t use!!

 

Roger

 

[Jaager]

6 hours ago, Roger Pellett said:

 IMHO, it’s all the same stuff.

I would place money on the compounds that polymerize - the vinyl and acrylic components - have one chemical company as their origin.  It is probably a toxic and hazardous process not cost effective to replicate in multiple locations.  The gemisch that is the commercial product  probably has a few more manufacturers but not as many as there are products.   Some are just rebranded.  If two companies have products in the same shaped dispenser, they probably come off of the same line. A line that forks just before the labeling machines.

 

PVA when polymerized looks like intertwined fungal hyphae.  The thinner the zone of just vinyl chains between two meeting surfaces, the stronger the bond.   Clamping pressure = bond strength.  The limiting factor is the amount of pressure the wood fibers can resist before they crush.

 

If a POB build has molds that are plywood,  it would probably be prudent to prime the areas that are end grain with pushed in and surface wiped PVA.  Let it cure and then bond the planking.

Edited February 28 by Jaager