Crisp glue lines in maple

[--Tom--]

Any good tips to get an invisible glue line in maple- I had an invisible join in dry fit, once glued and clamped I inevitably get a visible line at the join. Other woods like Ash and Beech and oak seem much more compliant to not showing the line.
Have been using classic Pva- would switching that to something else work? Any other tips/tricks suggestions.

It’s not a gap- but the glue line is visible as a line

 

[profchris]

Hot hide glue is your best bet, and you'll want the refined stuff for luthiers. I recently glued maple using the cheaper hide glue and got visible glue lines.

If glueing small pieces, household gelatin works as highly refined hide glue. But it gels in seconds so you need the wood hand hot to give you time to position and clamp. Adding a little salt extends the open time.

 

[--Tom--]

Ah interesting - does it need to be hot melt or worth giving the liquid WH sell a try?

 

[--Tom--]

Here’s a photo of the offending line

 

[mark w]

Here’s a photo of the offending line
View attachment 189811

Is that a round section?

 

[--Tom--]

Is that a round section?

Starts off as a solid piece, resawn, hollowed, then glued back together, before shaping into an almond profile.

Makes a saya for a chef knife - I always want the join to be invisible

 

[profchris]

Ah interesting - does it need to be hot melt or worth giving the liquid WH sell a try?

Liquid hide glue is brown, so I'd say no to that.

For cooking gelatine, just melt it with a little water in a cup floating in a bowl of recently boiled water, dilute to runny honey consistency once melted and use straight away. If you try this you'll want several test attempts because it gels so fast, but you can clean it off with warm water and try again.

For your knife saya I'd set the oven to 100C, warm the wood for 10 or 15 mins, glue and clamp, then back in the oven for 5 mins to re-liquify the glue. Take out, snug up clamps, leave to cool.

 

[mark w]

Starts off as a solid piece, resawn, hollowed, then glued back together, before shaping into an almond profile.

Makes a saya for a chef knife - I always want the join to be invisible
View attachment 189822


View attachment 189823

Looks good, Maple is always tricky. I just wondered if the glue line had opened slightly because of its "round" section. Do you hand plane the glue joint prior to glueing? I've found this helps enormously. I really can't see the benefit of hot hide glue as mentioned above, standard pva dries clear, I don't believe this will accentuate the glue line.

 

[thetyreman]

+1 on hide glue, it gives the best glue lines, just make sure to work very fast if clamping, the old cam clamps are best for that.

 

[--Tom--]

Kant twist clamps are my preferred - though spendy so am growing the set slowly. I don’t normally use the quick grips - with mini g clamps in their place - and don’t think I’ll use them again for this.

If going hide glue sounds like may need to repurpose a record vice as a vertical press to clamp it in one go.


Surfaces are hand planed flat true - dry fit focus is for seamlessness


The rounding happens post glue up - I keep everything as square as possible until glue up - helps with keeping it all aligned and for clamping whilst chiselling the recess out - and then post glue up clamping for planing the outside to shape.

 

[Citracal]

Hand planing both surfaces to ensure a perfect seam will be the most important factor for ensuring an invisible joint. I've seen plenty of joints in maple without hide glue that have no visible joint line so don't think hide glue is the issue here. In Ernst Joyce's The Technique of Furniture Making (and they don't get more legit than that) I remember him saying you can run a piece of chalk down the joint line before (but possibly after) glue up to ensure there is no dark line (would have to dig it out to see exactly what he said). You can also use a clear setting epoxy.

 

[Ollie78]

Try old brown glue, its a version of animal glue that is liquid and only requires warming in hot water rather than a proper glue pot.
I normally use titebond one for maple.
To be honest that glue line is not actually bad at all really.

 

[Hornbeam]

Hand planed joints are almost essential with harder woods. For clamping I would use lengths of bicycle inner tube wrapped around it. The tighter you pull the bands and the more wraps, the more clamping pressure. Sounds crude but it definitely works

 

[BillK]

I just use Titebond Original, no issues with that. It can be a bit of job to find the join line to draw it with a pencil sometimes. With maple guitar tops a translucent paint shows up any line a good bit worse than the bare wood, all been good with the TB so far