Giff
Established Member
More or less. A tiny pinhole. They do need filling if you spray paint them as the paint sinks in a bit. The hole is about 0.5mm Geoff
How would you clamp this glue joint?
- Thread starter Tetsuaiga
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Eric The Viking":2n3hqp6w said:
The idea isn't mine. Not sure where it originates from, though.
Tetsuaiga":2n3hqp6w said:
It's just a bit of sand, it doesn't disolve or react in any way with the glue. If in doubt, best to try it out on some scrap wood first. In any case, keep it away from the edges so not to dull any blades when planing.
custard
Established Member
Tetsuaiga I take my hat off to you for posting this question.
There are many things that distinguish a real craftsman from the average wood butcher. But high on that list is a methodical and considered approach to glue ups.
Personally I'd try and incorporate a dowel or a domino into the joint to prevent movement, I wouldn't use a biscuit as there's too much play with a biscuit, then I'd make up some shaped cramping blocks.
Good luck.
There are many things that distinguish a real craftsman from the average wood butcher. But high on that list is a methodical and considered approach to glue ups.
Personally I'd try and incorporate a dowel or a domino into the joint to prevent movement, I wouldn't use a biscuit as there's too much play with a biscuit, then I'd make up some shaped cramping blocks.
Good luck.
The Hide glue rubbed joint is the simple solution and providing the physical joint is tight will result in a very strong bond.
When gluing a bridge on a Guitar I apply glue to the surface of the bridge, place it in position and gently hold it there for 3 or 4 minutes. It's not even a rubbed joint. Just gentle finger pressure. The Bridge holds 40 Kg of string pressure, very little gluing surface area.
I've yet to have one fail in near 50 attempts. Of course other Guitar makers tend not to believe. It's far too simple to work.
Fortunately I'm not the only one to have the faith. I nicked the idea from someone who has been using the method for a few decades longer than I.
When gluing a bridge on a Guitar I apply glue to the surface of the bridge, place it in position and gently hold it there for 3 or 4 minutes. It's not even a rubbed joint. Just gentle finger pressure. The Bridge holds 40 Kg of string pressure, very little gluing surface area.
I've yet to have one fail in near 50 attempts. Of course other Guitar makers tend not to believe. It's far too simple to work.
Fortunately I'm not the only one to have the faith. I nicked the idea from someone who has been using the method for a few decades longer than I.
I had a go today at both hide glue and yellow with the pin. Both worked nicely.
With the hide glue I also heated the wood gently first and was't actually able to rub it as it set almost immediately. It seem to have done done the job well. I think I only put glue onto one surface, I can't remember whether that's the correct way now.
I used titebond later with the pins as I didn't want to wait around for the hide glue to be reheated and it worked nicely. I'm not sure how many times it's okay to heat a single pot either?
Thanks for all the help with this.
With the hide glue I also heated the wood gently first and was't actually able to rub it as it set almost immediately. It seem to have done done the job well. I think I only put glue onto one surface, I can't remember whether that's the correct way now.
I used titebond later with the pins as I didn't want to wait around for the hide glue to be reheated and it worked nicely. I'm not sure how many times it's okay to heat a single pot either?
Thanks for all the help with this.
Sounds like the Hide glue is too thick. Forget PVA consistency with Hide, it should be more like a runny, thin vegetable Oil.
You should be able to rub the piece back and forth several times (sometimes more) before it grabs.
You should be able to rub the piece back and forth several times (sometimes more) before it grabs.
This time I added 4 times the volume of water to 1 part of pearl glue, normally i've done 3 or 3.5 times. so it was more dilute than normal. The joint surfaces were both very smooth. Perhaps I made the wood too hot, i heated it on lower setting with a heat gun before.
Before i'd had a problem with it turning to a thick gel and becoming almost crumbly. This time seemed better, but it really did become too difficult to rub within 5-10 seconds.
Before i'd had a problem with it turning to a thick gel and becoming almost crumbly. This time seemed better, but it really did become too difficult to rub within 5-10 seconds.
5 to 10 seconds doesn't sound too bad. Anyway if the glue really was too thick you will end up with a visible glue line, not something that is wanted.
Just be a little careful when pre heating the wood. You are effectively altering it's moisture content and the joint can actually move, such that it becomes inaccurate. I use a hair dryer on it's lowest setting. In a workshop that is around 20 to 22 C you should have plenty of time to apply the glue and do a rubbed joint, so the hair dryer isn't needed. Something like a couple of minutes to apply the glue and start rubbing the pieces together. Pre heating is more for the winter months or complex glue ups.
Cold draughts are certainly to be avoided.
As for reheating the glue. I do it. I've kept the glue in the pot for 3 days and used it, although in the warmer months I mix fresh every day. It spoils much quicker in the summer than the winter. Best way to check is to glue up a series of offcuts, allow them to dry and destruction test them. In fact any new batch of Glue I buy goes through this type of test. Takes but a few minutes.
Just be a little careful when pre heating the wood. You are effectively altering it's moisture content and the joint can actually move, such that it becomes inaccurate. I use a hair dryer on it's lowest setting. In a workshop that is around 20 to 22 C you should have plenty of time to apply the glue and do a rubbed joint, so the hair dryer isn't needed. Something like a couple of minutes to apply the glue and start rubbing the pieces together. Pre heating is more for the winter months or complex glue ups.
Cold draughts are certainly to be avoided.
As for reheating the glue. I do it. I've kept the glue in the pot for 3 days and used it, although in the warmer months I mix fresh every day. It spoils much quicker in the summer than the winter. Best way to check is to glue up a series of offcuts, allow them to dry and destruction test them. In fact any new batch of Glue I buy goes through this type of test. Takes but a few minutes.
Bradshaw Joinery
Established Member
could you not clamp in both directions to stop slipping?
Do you leave the glue to absorb water for 12 hours? That's what the stuff i've got says, it's liberon pearl glue.
12 hours is a long wait if you hadn't planned in advance that you'd need it.
i'm not sure if I could clamp in both directions, but I think hide glue has solved my problem now.
12 hours is a long wait if you hadn't planned in advance that you'd need it.
i'm not sure if I could clamp in both directions, but I think hide glue has solved my problem now.
I buy it from kremer Pigmente. You can buy similar stuff from Touchstone Tonewoods in Surrey. It's Hide glue and is much clearer than Pearl. You can always crush the pearl glue though. That will help it absorb the water much quicker.
Hide usually has a higher gram strength than pearl and is therefore a little stronger. The higher the gram (or bloom) strength the stronger it is but the less open time you have. In fact it etches glass, my little glass container is half eaten away! For woodworking applications around 140 - 260 Gram strength is the norm but the stuff goes much higher. I think Pearl is towards the lower end of that scale but it is perfectly adequate for wood joints.
You can also buy liquid Fish glue from Kremer. That is ready to use out of the bottle, cold, is high tack and gives a very long open time. Hide is better for rubbed joints though. Fish if you have long complex glue ups. Both clean up with water, Hide being a little easier. Fish seems to be mighty strong.
Hide usually has a higher gram strength than pearl and is therefore a little stronger. The higher the gram (or bloom) strength the stronger it is but the less open time you have. In fact it etches glass, my little glass container is half eaten away! For woodworking applications around 140 - 260 Gram strength is the norm but the stuff goes much higher. I think Pearl is towards the lower end of that scale but it is perfectly adequate for wood joints.
You can also buy liquid Fish glue from Kremer. That is ready to use out of the bottle, cold, is high tack and gives a very long open time. Hide is better for rubbed joints though. Fish if you have long complex glue ups. Both clean up with water, Hide being a little easier. Fish seems to be mighty strong.
http://www.toolsforworkingwood.com/store/item/AQ-1131
There's a book for everything. I haven't got the book but it's one I really should have. Same author has one on: Shellac, Linseed Oil and Paint (another that I should have), along with a book on American 19 th century woodwork.
http://www.woodworking.com/ww/Article/G ... -4753.aspx
There's a book for everything. I haven't got the book but it's one I really should have. Same author has one on: Shellac, Linseed Oil and Paint (another that I should have), along with a book on American 19 th century woodwork.
http://www.woodworking.com/ww/Article/G ... -4753.aspx
