Rubbed joints its success and failure

As sprung joints are great for clamping two edged boards together to make a panel, they are disastrous for non clamped rubbed joints. To avoid following the footsteps of magazine articles, I will not go into detail of what a rubbed or sprung joints are.  I believe that you are well passed the novice stage and I don’t feel it would be beneficial in re reading something you already know,  but would rather bring to your attention to something you may not have been aware of or unintentionally overlooked.

There has been a strong emphasis awarded to sprung joints, many articles and videos have been written and produced stressing the benefits of such a joint. While I don’t disagree with them, sometimes the obvious tends to skip us and we continue to apply a certain technique that has been drummed into our heads by an almost hypnotic suggestion through the continual parroting of others, that would lead to disastrous results if we were to apply the same technique using a different application. This issue I feel needs not be overlooked, but addressed in any future articles written on the subject.

The success of a rubbed joint is comprised of only two things, glue and two perfectly straight no gapped edges. A sprung joint as you know has a 32nd hollow in the middle, creating a successful rubbed joint would not be possible. The other point is the type of glue that best suit a rubbed joint would be hide glue. True, you could get away with small thin pieces using ordinary PVA or other quick setting PVA glue, but for a small cabinet or bedside table or even a coffee table, only hide glue in my opinion would be better suited for a such an application ie. rubbed joint.  I have written in my previous posts on the benefits of hide glue so I won’t go into any great depth on the subject here, other than to add, only hide glue as far as I know, has the capabilities of drawing two mating edges together as it dries, forming a good solid join and for that to happen there cannot be any gaps.

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6 thoughts on “Rubbed joints its success and failure

  1. As much as I like hide glue, I have yet to use it for laminating panels. I typically use PVA for laminations and hide glue for most everything else. I’m not all that sure about the whole spring joint thing. I know some swear by it though. I go for an exact match at the joint line. Hasn’t failed me yet.

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    1. I gather you have little faith in the strength of hide glue, rest assured despite all the doubt that has been put out there hide glue is super strong. Remember before PVA every panel glued up was with hide. It’s 8000 years old while PVA is only 77 years old. You know I don’t have any qualms with PVA in fact every PVA glue on the market works well, there is no one better than the other but hide glue is just as strong is all I’m saying.

      Sprung joints are excellent if your clamping but for rubbed joints how your doing is the correct method. I thought I’d inform everyone because sometimes we get so caught up with what the celebrities are saying that we miss the obvious and they too miss adding the obvious.

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      1. On the contrary, I have absolute faith in the strength of hide glue. My main reason for using PVA for panel glue ups is convenience. It takes a good bit of prep, as well as volume, to use hide glue for glue ups of this kind.

        You advice and information is sound though.

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      2. I appreciate what your saying but I disagree as it takes no more volume of glue to slap on as it does with any other glue. But I think the fear is in the quick cooling down stage, this is easily remedied by placing a warm iron on the edge prior. But in all honesty I’ve never had to do it, for marquetry I think possibly so. But I do agree that it is time consuming setting it up and considering that in a one man shop whether your professional woodworking or amateur hobbyist you don’t glue up everyday, so I don’t see it being an inconvenience at all. Since I know that liquid OBG is equal in strength to the stuff you mix up I tend to use it more than I do prepping it. By the time I get my clamps ready the bottle has been heated enough for use. If I had to glue up everyday it would be costly using liquid hide but one 20oz bottle will give me more than a year of use. For prototypes that I need glued in a hurry I will use a quick setting white glue, 2 mins she’s rock solid, 4 hours it’s cured and most probably by then in the bin.

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      3. I’m not saying that it takes more hide glue than PVA. What I mean is that, depending on the size of the glue up, I will need to mix up more than my usual volume of hide glue. I would hate to come up short. The prep that I am referring to includes heating the glue and the material. Since I work in short bursts and try to get all of my glue ups done during the week, the extra prep time can be a problem.

        Liquid hide glue can be a solution. I have been meaning to try mixing up my own liquid hide glue using either salt or urea.

        My biggest issue is that my need for glueing up panels or laminations goes in spurts with sometimes weeks going by before I need to do another one. So for now PVA is a simple option that is always ready when ever I am.

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  2. Yes I cannot argue with on this as you are correct, wastage is an issue and so is prep work. Making your own batch of liquid hide is a good idea and much less time consuming once it’s all bottled, just heat and go. If you are going to do it I would recommend using salt instead of urea. Reason being if you mix urea there is a 12 months expiration date but salt it’s indefinite. Before fridges were invented people used to salt their meat and leave it out in the sun to dry, it kept and didn’t go off. As hide glue is an animal product the same applies to it. I’ve never made my own batch but you’ve now inspired me to do so, if you know how much salt is needed for the mix please let me know.

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