Spreading glue in mortices

[Tom Bender]

There are lots of ways to spread glue on flat surfaces but today I have to spread it into some deep narrow mortices and groves. And I have to do it quickly and accurately. The little plastic trowels are too short and small. Any suggestions?

[Bob Riefer]

I use small paint brushes from Harbor Freight and find I can get glue where I want it pretty accurately and consistently

[Jared Sankovich]

Acid brush

[Jamie Buxton]

I use a 6" machinists rule. It works as a thin narrow spatula. It easily spreads glue into a mortise, and is easily cleaned.

[David M Peters]

+1 to acid brushes! They wash out well under warm water.. I've only used a few from my Harbor Freight 30 pack.

[Jim Becker]

Acid brush (they actually come in multiple sizes) as they are disposable, although you can wash and reuse a few times and for larger glue-ups, I have a silicone glue brush. One of the challenges is not getting too much glue in there, too.

[Earl McLain]

I have some polyester swabs that I use for that kind of stuff. Like cotton swabs, without the fibers.
earl

[michael langman]

I save the sticks from popsicles and ice cream bars and use as spreaders for glueups.

[Bill Dufour]

Silicone barbecue sauce brush with pot.
Bill D

[mike stenson]

Acid brushes and pallet knives. Although I prefer the knives for dovetails.

[Jim Dwight]

I use acid brushes sometimes but recently I have used a Rockler silicone brush more. It has a flat end in addition to the brush. I like to shove that flat end into the mortise to spread the glue. I use the brush to put it on the tenon. If the mortise was too small for the Rockler brush I would just use an acid brush - or fashion a little tool out of scrap.

[Christian Hawkshaw]

I save the sticks from popsicles and ice cream bars and use as spreaders for glueups.

I do something similar, but save scrap thin rip cutoffs, cut to about 10 inches in length. I usally apply a bead of glue to top of the mortise wall with a squeeze bottle, and when the glue starts to drip down, use the the "paddle" to spread the glue.

[Bob Riefer]

I never knew the "little paint brushes" that I use are actually "acid brushes". Learn something new every day

[Richard Coers]

Telling us the size of the mortise sure would help. Popsicle craft sticks work for larger than glue brush size.

[John C Bush]

Usually acid brushes and disposable paint brushes for wider surfaces. I trim 3/4+"s of the tip--makes the brush stiffer and moves the glue more easily. Someone left a Rockler silicon brush and glue tray in my shop and I grab it first now instead of the acid brushes. Old Dogs???

[Charles Taylor]

All good ideas. Wooden coffee stirrers, which look like popsicle sticks but narrower and thinner, can be useful too, depending on the size of your mortise.

[Rob Luter]

A toothbrush works pretty well too.

[johnny means]

I use a set of those gun cleaning brushes. They come in several sizes and work on dowel/Domino holes perfectly.

[Myles Moran]

I use acid brushes most of the time. For the 1/4" mortises I'll usual flatten the acid brush with a hammer to let me get it in the mortise more easily without making a mess.

[William Hodge]

I make through tenons. I use a 10" long pine wedge freehand on the band saw, almost as wide as the mortise, tapering to a sharp edge ant the glue end. I can dip it in glue, smear the mortise walls and shoulders, and have enough left for the tenon, cope, and shoulder. after the mortise and tenons are all glued, I toss the stick in a can of water while I clamp. I wipe the stick off after assembly, before gluing up the next pieces.

The wood is free, and there's nothing to throw out.

[Alex Zeller]

If the mortise is small I've used Q-tips. Slightly larger I use a small paint brush.

[Carl Beckett]

For some reason acid brushes never really clicked for me (always seemed messy and getting glue around the edges I didnt want). I have some longer wooden 'q-tip' type swabs I use. Often I break the tip off which just makes them a small round stick. But I dont really see some fiber from the swab being a big deal.

Often used is a small screwdriver I have. It is a bit longer than a standard screwdriver. The flat on the end is good for buttering up with glue which I can then rotate and spread the full depth in one pass. Just wipe to clean it since its metal (if it dries on there it peels off easy).

As I think about it the same things I use to spread glue are what I use to mix two part epoxy in small batches.

[Greg Quenneville]

https://www.burnstools.com/media/wysiwyg/pdf/d41567f643ff4be5ba28549a1c0b05f9.pdf

[Tom Bender]

Thanks all for the quick reply. It seems like I have not missed out on any ingenious solutions. It's just common sense. I have made a few paddles for the mortices and the plastic paddles will be fine for the grooves, which are shallower.

477603

[Stan Calow]

I trim the acid brushes so they are not too wide or have loose hairs. The wood popsicle sticks to scoop a lot of glue quickly - you can get bags of these at hobby stores.

[Rod Sheridan]

Acid brush

Exactly what I use, buy the expensive ones with stif bristles, they work much better than the softer ones for getting into mortises….Rod

[Jack Frederick]

Having been in the pipe trades I buy the acid brushes by the box. The grandkids know where the box is so I go through them pretty quickly. We always called them flux brushes. They are best stored next to the capacitor.

[Jeff Roltgen]

Acid Brush users: hit the well of the brush, where bristles are cramped in place, with medium - thick CA glue. Shot of activator and in a few moments, you have a brush that no longer sheds.

I just received the large and small silicone glue brushes from Rockler, so no insights on those yet. Just trying another method, maybe saving a fistful of acid brushes going into the landfill each year. It all adds up.

As for the initial question, I keep buckets of thin rip drop-off waste from table saw, which serve to spread glue, custom shaping ends for all manner of tasks, including the glue, but also wood fillers for hard to reach areas. If you were talking domino mortices, I like to slightly round edges of a flat stick to assure full coverages of the round ends of mortice.

jeff

[Thomas McCurnin]

Long wooden coffee stirrers and little brushes. The brushes come in ⅜ and ¼.

[Jonathan Jung]

Wood stir sticks (coffee stirrers) for small mortises and wood tongue depressors. Get them in a 1000 pack. Work like spatulas mentioned above. Drip glue in mortise and pull it up the sides with the sticks. Super fast.

[Jim Becker]

Acid Brush users: hit the well of the brush, where bristles are cramped in place, with medium - thick CA glue. Shot of activator and in a few moments, you have a brush that no longer sheds

That's an EXCELLENT tip!!

[Clifford McGuire]

Having been in the pipe trades I buy the acid brushes by the box. The grandkids know where the box is so I go through them pretty quickly. We always called them flux brushes. They are best stored next to the capacitor.

:) I alway keep a set in the Delorean!

[Mark Hennebury]

Get yourself one of these pressure pots.

https://www.mddionline.com/sites/mddionline.com/files/images/9805p56b.jpg

[Thomas McCurnin]

Coffee Stirrers

[Brice Rogers]

When I go to starbucks I usually pick up a dozen or so coffee stirrers. In addition to spreading glue, I like using them for mixing and applying 2 part epoxy.

[Myles Moran]

Thanks all for the quick reply. It seems like I have not missed out on any ingenious solutions. It's just common sense. I have made a few paddles for the mortices and the plastic paddles will be fine for the grooves, which are shallower.

477603

Are those finger joints inside the mortise? Now that's a skill showoff.

[Alan Schwabacher]

For box joints I use a foam brush cut into the same size fingers. This allows one swipe to cover all the mating surfaces. On flat surfaces a credit card works well, and is easily trimmed to the width you need for mortises.

[Mitch schiffer]

I like the silicone brushes from rockler. They have a couple different sizes depending on how big you mortise is.