How long do you let a glue up dry before you start machining?

[George Bokros]

Just wondering how long it is necessary to let a glue up set before you start planing for thickness?

Thanks

[Rod Sheridan]

I normally let glue cure overnight............Rod.

[jim mills]

Lot of variables here. What type of joint? What glue? Temperature can play a factor as well. If we are talking PVA, bottle says 24 hrs before stressing, but I will admit to bending the rules in a pinch.

[Michael Zerance]

I usually try to wait a day or two but I am confident with taking small bites on the planer after just a couple hours. I have run panels through the planer as soon as one hour after gluing without any issues.

One thing to consider is that the wood expands very slightly at the joint from the moisture in the glue. If you plane and sand the panel flat too soon after gluing it up, the area along the joint will shrink slightly once it dries out. This leaves very minor indentations along the joint line days or weeks after finishing the project.

[George Bokros]

Lot of variables here. What type of joint? What glue? Temperature can play a factor as well. If we are talking PVA, bottle says 24 hrs before stressing, but I will admit to bending the rules in a pinch.


Edge to edge glue-up using TBIII. Temp is probably 65*+.

[Chris Padilla]

At least a 1/2 day but like Rod, I like to leave it overnight before I start hammering on it. However, it depends on the glue and the clamping situation, too.

[Jesse Busenitz]

Depends on how big of hurry I'm in. I've planed a glue up that only dried a hour before and it worked fine, but I normally try and wait a little longer.

[John K Jordan]

I leave Tightbond clamped overnight. I believe the instructions say you can remove the clamps earlier and don't stress it for 24 hours but I have plenty of clamps. I use it for glueups for woodturning and if the glue is not perfect it's ruined in a millisecond.

Here's one, endgrain to side grain. Cherry, walnut, basswood:
326308
JKJ

[Prashun Patel]

I've heard (but never witnessed) that the moisture can continue to leave a Titebond joint for a day after and cause the surface to shrink if you plane it flat.

I usually wait about 6 hours for plugs and I haven't had issues. On show panels where I really don't want a visible glue line, i leave them glued and clamped overnight until the glue is hard to my finger nail.

Mostly I try to wait overnight. At least, I don't stress the joint for that long.

[Doug Hobkirk]

Didn't Fine Woodworking find that TB had at least 80% of it's strength after 30 minutes?
I would love to know if this is right or wrong.

[Bill Orbine]

I've heard (but never witnessed) that the moisture can continue to leave a Titebond joint for a day after and cause the surface to shrink if you plane it flat.

I usually wait about 6 hours for plugs and I haven't had issues. On show panels where I really don't want a visible glue line, i leave them glued and clamped overnight until the glue is hard to my finger nail.

Mostly I try to wait overnight. At least, I don't stress the joint for that long.

Yes, it happens. If you plane glued up panel the next day the ridges may or may not show especially after finish. However, the effects of this lessens if you sand the panels (the project) later when you're near completion of the build (after at least a few days) and getting you're ready to stain/finish. The glue joint can be problematic if the project is a one-two day quickie. It's a big deal if the panels are something like a tabletop and YES, I give it more time.

Normally, I'm a minimum one hour clamper and minimum 24 hour stress when it comes to glue joints. Always a few days before final sanding.

[Ken Fitzgerald]

I prefer to wait a minimum of 4 hours before removing clamps and 24 hours before milling.

[Bruce Page]

I try for overnight drying but I've gone as little as 2 hours.

[George Bokros]

Thanks for all the replies. Most everyone is of the same thought as me 24 hrs before milling.

[Jim Finn]

I normally let glue cure overnight............Rod.
\Same here

[Leo Graywacz]

Summer 45 minutes, winter 1:15. I'll plane or mill it as soon as it's out of the clamps. It will need to dry/cure for 3 days before I'll put a finish on it though. Otherwise you can get telegraph lines showing through the finish.

[mreza Salav]

Regular PVA glue doesn't really need clamp more than an hour or so (I even sometimes open after 30 minutes if I am really in a rush).
As for machining, I try to wait at least 6 hours but have done much sooner (like 2-3 hours) and no issues.
If you have ever tried to undo a joint after 30 minutes you might realize how strong the joint is after such a short period.

[Wade Lippman]

I started woodworking in a weekly evening class, and if you let the glue ups sit for more than 30 minutes you would never get anything made.

I now try to leave a few hours, but I am sure have done 50 glue ups with no more than 30 minutes before proceeding and have never had a problem.

[John Lankers]

I personally let panel glue ups, especially with spring joint clamped over night. Cope an stick or bridal joints more like an hour or so, I made some try squares the other day and took the spring clamps off after 30 minutes. It all depends on the situation, I think a good fitting joint is more important for success than clamping time.

[Rich Engelhardt]

I left the raised panel doors I made for my roll around kitchen cart dry for 24 hours before I planed them.
Darned things nicked the planer blades and left lines in the panels....

[Curt Harms]

Didn't Fine Woodworking find that TB had at least 80% of it's strength after 30 minutes?
I would love to know if this is right or wrong.

I recall 2 hours to reach 80% strength but don't have a citation. I imagine temperature and maybe humidity enter into it.

[Mike Henderson]

You specified planing the material. For that process, I like to have the glue set for several hours. For other processes, I've worked on the material in as little as 30 minutes.

When I took woodworking classes, one instructor took two pieces of wood, rubbed titebond on the faces and held them together while he lectured for a few minutes. Then handed the wood to a student and asked him to separate the two. Couldn't be done.

I use PVA for veneering in a class I teach and leave the panels in press for 30 minutes. They are fine but you can't put any water on them for a while (water is used to remove the veneer tape). If you do put water on the panel, you risk a bubble where the glue detaches.

Mike

[Mark Blatter]

When I am doing commercial shelving which involves making a large number of shelves, I time them at 20 minutes. I can clamp up about four shelves in twenty minutes, so once I get the fourth one clamped, I start removing the first shelf I did. I write the time I finish clamping on each one so I know the time for sure. I have never had an issue removing the clamps at 20 minutes. I have caught mistakes after 4-5 minutes and could barely pull the two pieces apart. I don't even try after 7 or eight minutes because I know the wood will start to break instead of the glue.

I don't work a glued panel at that point, which was the question. I prefer to wait at least 4-5 hours and when I can, I wait a day or two before planing or even sanding.

[guy knight]

i do a lot of glueups with TBIII and unless the joint is under pressure during the winter an hour with no problems but i wait a day to apply a finish for cabinet doors i clamp like 15 minutes and have never had a problem

[Mark Patoka]

I usually try to do my glue-ups before I clean up the shop for the night and then they are ready for the next day so typically 24 hours. I also try to plan out any weekend work so a glue-up can sit ~24 hours before working it.