Both Probond and your regular wood glue state “Not for structural use.”
How can this be? What else is it for?
I am a professional woodworker; if these products are not designed to be
wood glues, shall I return them?
Dear D. Cassidy,
Thank you for contacting us regarding Elmer’s products.
Elmer’s wood glues are designed to provide extra support for mechanical fasteners (i.e. nails, screws, bolts, etc…). One should never rely on a glue alone when dealing with load bearing joints. I hope you find this information helpful and look forward to serving you as a satisfied customer in the future.
Sincerely,
Brian Rumschlag
Consumer Response Analyst
Replies
What the heck!!!!!........... they actually said it is not to be used for load bearing joints........Give me a minute to get my mind around this one....... Aren't most woodworking joints at one time or another load bearing or at least could be considered so? Maybe they should call it something instead of glue to avoid further confusion.
Thanks for bringing this to our attention.
-Paul
Yeah, I found it odd. I suppose it depends on "load bearing joints"- what his definition is. I don't know if it's just for liability issues or if it's the product itself.
It sounds like a CYA situation. It will give me pause the next time I reach for the Elmer's when gluing a joint for a dynamic application. I'd be curious what other MFG's would say?
-Paul
About the only furniture joint that doesn't have mechanical support is edge joining to make panels. Dovetails, mortise and tenons, dowels, biscuits, gluelock, and dado's to name a few all have a mechanical component. How many of use use bare butt joints to secure anything.
Steve,
Yeah, I agree with your assessment of furniture joints. What concerns me is the lack of a clear definition by the manufacturer of what load bearing is. I guess what I was thinking about were situations where you really depend on the glue as with stacked or bent laminations. Particularly the number of times I've glued up blanks for turning or carving some large architectural element or the like. I may re-consider my choice of adhesives the next time.
-Paul
The words "structural" and "load bearing" are commonly recognized as referring to buildings only. The warning about not using the glue for structural or load bearing purposes is only about that, it says nothing at all about using the glues for furniture work.
John White
The words "structural" and "load bearing" are commonly recognized as referring to buildings only.
Rule of thumb: a joint is "structural", if, when the joint fails, people die. 'doesn't apply to furniture.
A good simple rule, I made the same point, but not as clearly, in an earlier posting.
John W.
"How many of use use bare butt joints to secure anything?"
Hi Steve,
I thought a "Bare Butt Joint" was one of those so-called gentlemen's clubs that feature "live nude girls" (as opposed to what? Dead nude girls?), frequented by the kind of guys one would refer to as a gentleman only under the most charitable of circumstances.
You're right: I eschew bare butt joints of both kinds,
-Jazzdogg-
"Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive." Gil Bailie
Jackplane,
These glues remain plastic even when fully cured and can "creep" under load. But it's a pretty good bet that anything you make as a woodworker will be "safe" using them in your joinery.
There are very few joints in which there is not some mechanical resistance to movement in addition to the adhesion of the glue. And even when there is not, the possibility of a glue line failure is nil. An example is a table top glued up of planks, edge jointed with white glue.
There are other glues which don't "creep" such as epoxies, hot hide and polyurethane which might be more "structural" type adhesives.
Rich
Rich,hot hide, "structural" type , I don't think so.
Hilmar
Yeah,Shouldn't oughta said that. I meant it won't creep.Rich
The key words here are "structural" and "load bearing", which have specific meanings to an engineer, or a lawyer, and which the Elmer's rep didn't help to clarify at all.
Structural and load bearing, as used in their warning, means supporting weight in a structure, such as a house, or more generally, a building. They don't want you gluing a balcony onto the side of a house for instance, or gluing a stairway to a landing. Basically they don't want the glue to be used in a situation where life and limb would be at risk if the glue failed, which isn't an unreasonable restriction for glue you are buying off the shelf at a Home Depot.
For most structural situations mechanical fastening is the typical means of attachment, glue, if it is used, is there to provide additional reserve strength or to prevent movement that might make a floor squeak for instance.
The recent tragedy in the Boston tunnel where a car was crushed by multi ton slabs of concrete falling from the tunnel's ceiling, on first report, shows the limitations of using glue for structural purposes, although the cause is still being investigated.
John White, Shop Manager, Fine Woodworking Magazine
The French use a quite colorful expression for screwing up; "chier dans la colle".
It literally means to "poop in the glue".
I guess somebody took a major poop in the big dig's glue !C.
I guess they did "chier dans la colle" in Boston, but it is sad that someone innocent died because of it. I find it hard to believe that they hung the slabs off of bolts that were reportedly just epoxied into holes in the tunnel's ceiling.
John W.
We will never know the truth about that, the coverer uppers will do the covering up, the politicians will lie as usual, the guys that made tons of money on the side are still laughing. The blame will bounce back and forth.
The poor lady died and nobody gives you know what.Diapers and politicians need to be changed often for the same reason ! C.
if that's true and it may be, then it's a disgrace!
JWW, no supprise to me as I was faced with the same problem that involved four 3/4" mounting bolts in the corners of poured and reinforced pedstals for lamp posts in a very large corporate garden. The engineers DEMANDED the use of chemical fastening of the straight 12" long bolts rather than the traditional use of "L" bolts buried in 14"of reinforced concrete. The electrical sub(our favorite who maintained our 40 story bldg) was stunned but had no choice but to follow the spec provided. The hammer drilling of the holes and the NASA type price of the glue increased the time and cost by thousands of %, but the big costs make the high eng fees look relatively smaller Eh? It is a pity that the new book learned engineers fall under the spell of suppliers, prehaps for an invite to a nice product demo junket or box seats or two on the aisle? Pat
Amen to that. It is a constant struggle to try and explain to people who sit behind a desk with no actual hands-on knowledge why things are done a certain way.
We don't have the time to do it right, but we have the time to do it over?
-Paul
I studied to be an engineer but spent my whole life in the trades, nothing surprises me anymore.John W
I thought they were using bolts, too. If I read the article correctly, the bolts AND adhesive failed. It was a deviation from what was spec'd on the materials list that caused it, IIRC. That's major lawsuit time."I cut this piece four times and it's still too short."
Edited 7/17/2006 10:30 am by highfigh
Newspapers tend to get technical details garbled, but it sounded like they were hanging the panels off of threaded rod anchored into the tunnel ceiling with epoxy. This is a quote from the Boston Globe: "Each panel was secured by eight bolts. The bolt ends were coated with epoxy and inserted into drilled holes in the ceiling. This created a second, lower ceiling, that formed the ventilation passageway."
An accompanying photo of a failed connector shows a piece of what looks like ordinary 3/4 inch diameter threaded rod stuck into either a piece of the tunnel ceiling or one of the panels. The pulled out rod is covered with what is probably the white epoxy adhesive and has a red plastic collar that probably served to seal the gap between the projecting end of the rod and the hole. Another photo shows a steel plate from the accident scene, the plate was attached to either the ceiling or the panel with four of the epoxy covered bolts, one of which is still there. The plate has three turnbuckle type rod ends attached to it that probably made the connection between the ceiling and the suspended panels.
If they really just hung 3 ton concrete panels on glued in straight rod somebody was incredibly stupid.
John W.
Edited 7/17/2006 11:16 am ET by JohnWW
Edited 7/17/2006 11:33 am ET by JohnWW
"But the label said......". That IS stupid. I don't even like using expanding inserts in a ceiling.
"I cut this piece four times and it's still too short."
naturally, the next question is: when will the next 3 ton panel come crashing down?
I'm speculating, but I'm guessing that on paper, the engineering looked fine. Once is came to actually implementing it, is where the difficulties were.
I'm thinking about that hotel balcony collapse in Kansas City. The engineers designed a support system that would have worked, just barely. The problem was, it was near impossible to build, so the GC made a minor (or it seemed minor to them) change so that the thing was buildable. This changed weakened the design enough so that it failed.
It should be possible to engineer an epoxied system. But the devil is in the details; e.g, you need to get those drilled holes perfectly clean of all dust. You need to have no voids in the epoxy. How possible do you think that is to do, consistantly?
PL-1000 would have done the job. If it hadn't been sitting on a shelf for 5 years, the holes were spotless, it was the right temperature, humidity, baro, the person applying it was in a good mood, their biorythms were right for that particular job, etc. At 3 tons, I don't think I would spec it without mechanical fasteners. Just kidding about the PL-1000.
"I cut this piece four times and it's still too short."
Where is the accompanying photo? Yes, a bond line loaded laterally, as you describe, & subjected to the vibration of traffic is an unbelievable mistake. It also seems a mistake to use concrete for ductwork when much lighter weight materials are easily available. Had I been in Boston & known of such structural details, I would never have gone into those tunnels. Should we suspect criminal activity?Cadiddlehopper
Is stupidity a crime in Massachusetts?
John W.
John,
Thanks for the clarification. Must be a case where they are vague on purpose?
-Paul
If stupidity were a crime anywhere we would be without politicians.
Since the house is on fire let us warm ourselves. ~Italian Proverb
I think it is not a crime anywhere. I'm thankful, too, or I would be doing time. A better question may be: Is committing a crime stupid?Cadiddlehopper
Depends on the crime, not all crimes are immoral. Chances are you did'nt make it through the day without commiting a crime. It would take years just to read through all the laws on the books.
Since the house is on fire let us warm ourselves. ~Italian Proverb
The two most abundant elements in the universe: hydrogen and stupidity.-Jazzdogg-
"Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive." Gil Bailie
One need only to review election results to determine the answer.Regard it as just as desirable to build a chicken house as to build a cathedral. Frank Lloyd Wright
Cad,
I'm not that John mentioned there are several engineering firms involved. Each section was engineered by a different firm and most used the same bolt/epoxy solution....quite strange.
However, the budget was 2 billion....and to come in under 15 billion they probably needed to make cuts somewhere....
Roof bolts are standard in the mining industry. (try Google) Several types are used instead of the old timber cribbing to support the rock ceiling as the tunnels advance . The epoxy type are inserted into the hole drilled into the ceiling rock and "spun" to blend the two components. Who knows what went wrong in Boston.Frosty/Jerry
I'd bet a Coke that that it's a combination of engineering and contractor errors and procedures. My bet goes like this-The fastening system works fine (i've used fasteners of this type) holding up a cieling segment under normal conditions like vibration..etc. When it came time to do the install, there was some Minor/major variance that made the contractor change the installation procedure. The contactor never cleared the variance (or as built) with the engineers. The variance that was completed, didn't allow for the redundacy of single or multiple hanger failure. The engineer also didn't allow a factor of safety high enough to compensate for some variances (thus undersizing the system). When these two factors come together, the fasteners couldn't carry the load once one or multiple fasteners started to fail. When there is no redundancy during a failure, things talk pretty quick and stuff falls down.
Read "Why building fall down" it sad but very interesting. It points out that time and money are mostly the cause of loss of life.Magnus
"Remember, a bad carpenter always blames his tools" -Joe Conti-
Geeeezz!! Should I exchange the gallon I bought yesterday for some Titebond?
Cadiddlehopper
I like titebond - it is my default glue.
As far as the load bearing issue goes, my feelings on that would be them CYA where someone will butt joint a shelf and glue it in place and then expect it to hold the encycoledia brittanica on the 1 shelf - no rabbets, no dados, no dowels, biscuits, nails or screws - just a glued butt joint ( and it gets the munchies don't you know ).
1 - measure the board twice, 2 - cut it once, 3 - measure the space where it is supposed to go 4 - get a new board and go back to step 1
I think I'll stick with Titebond, which clearly states on the bottle that when dry it's stronger than the wood that it's gluing together.
If they indeed were thinking of structural framing applications (i.e. houses), that's not a good excuse. It should have been pretty obvious that the person had woodworking in mind, and was worried if their glue was suitable for, for example, a kitchen table.
And who would use a wood glue for structural framing anyway? Isn't that what "construction adhesive" is for? Sounds like Elmer's needs to figure out who exactly they're trying to market to.
Edit: I just reread the first message, and he clearly states that he's a professional woodworker. Do the idiots at Elmer's not know the difference between a woodworker and a timber framer?
Edited 7/15/2006 2:44 am ET by dwolsten
>> I think I'll stick with Titebond, which clearly states on the bottle that when dry it's stronger than the wood that it's gluing together.Contact Franklin (manufacturer of Titebond). They too, will tell you their adhesive is not for structural or load bearing applications.There is virtually no difference between any manufacturer's PVA adhesive. They all have the same characteristics and specifications. All are "stonger than the wood itself".Howie.........
"...Titebond, which clearly states on the bottle that when dry it's stronger than the wood that it's gluing together." Can be said of most modern wood glues, IIRC. The marketers like to use that statement as if it's an exceptional thing. I do love TBIII though.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Do the idiots at Elmer's not know the difference between a woodworker and a timber framer?
Very likely the 'idiots' are lawyers, and they put that crap on there because they figure that somebody will try to build a house with it and not use nails, and then when the thing falls on them sue the pants off Elmer's. My opinion (which isn't any better than anyone else's) is that the glue is glue and the type on the bottle and words from the rep come from the legal department and not from the glue department. I use other glue than elmer's, and found others better overall for strength. The point is, there are folks out there that really don't know the difference between a woodworker and a timber framer, but it is usually a consumer.......
A friend of mine from Oklahoma told me about a guy in his town that learned "glue is stronger than the wood," so he glued up his trusses for a roof. This worked until one summer day when the roof got hot (remember it's in Oklahoma) and the whole thing collapsed.
Well, there you go, the lawyers dream. Yes the glue is stronger than the wood, but there are limits to it. If I were guessing, I'd say that the wood sheered and left the glue joint mostly intact, meaning that there wasn't enough surface area used for a joint bond. That is why trusses that have those plates pressed together work, there is a lot of bonding surface area to hold with and not just a end of a board or a face to face bond. Common sense should have come into play here, don't you think? I figure that anything that has weight applied to it needs to have some kind of support and glue alone won't cut it, I like to make my stuff so that the joint could hold it together if there wasn't glue and edge glued boards are supported in some way by another joint. Stuff that doesn't have any weight on it can stand on its own with glue in most cases, but I usually use biscuits or something like that too for extra help. When they say on the bottle is not for structural bond, I always thought it was meaning not strong enough to be used for gluing table legs to a table, or bed rails to a headboard and the like, never did I ever think that it could be used for framing in construction. I guess I just had that much common sense?
Edited 7/16/2006 7:46 am ET by pcooper
I don't think you'll find a single glue in a woodworking store or catalog that the manufacturer wouldn't say is "not for structural use". Such glues would need to be suitable for use in load-bearing building framing, approved for such use in a model building code, and listed for such use by a qualified testing laboratory. Why would a woodworking glue undergo such testing?
Structural glues, like those used to assemble glulams, are usually 2-part resorcinol adhesives.
Edited 7/17/2006 2:42 am by BarryO
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