Trad Gang

Main Boards => The Bowyer's Bench => Topic started by: CamoZ on February 25, 2013, 11:15:00 AM

Title: My glue line is too noticeable..any suggestionsÉ
Post by: CamoZ on February 25, 2013, 11:15:00 AM
In finishing my first bow I notice that the riser glue line is very apparent..I am starting on a Hickory bow soon and I wonder if anyone has tips on how to make a cleaner, less noticeable glue line.
Title: Re: My glue line is too noticeable..any suggestionsÉ
Post by: macbow on February 25, 2013, 12:19:00 PM
Of coarse the wood matching up before glue up is the first step.
Then clamp pressure and clamping evenly across the span.
If a clamp slips a little to one side it will flex everything.
Title: Re: My glue line is too noticeable..any suggestionsÉ
Post by: Bowjunkie on February 25, 2013, 01:40:00 PM
It will get better with experience. Quality of glue lines depends on which tools you use and your skill with them, glue surface prep, clamping pressure, etc. Without knowing/seeing those things, it's kind of hard to advise changes.

For gluing handle pieces onto blanks, I like to shape them so they're mated perfectly, then prep with a toothing plane blade, then glue up with epoxy, clamping firmly. With the grooves from the toothing plane blade on both gluing surfaces, it's virtually impossible to overclamp and starve the joint of glue.. Glue lines are almost always invisible.
Title: Re: My glue line is too noticeable..any suggestionsÉ
Post by: CamoZ on February 25, 2013, 08:26:00 PM
Hmm..virtually impossible to over clamp and starve..Good to know as I tried to account for starvation on this clamp up..I wont worry next time..I just read about the toothing plane..I will be getting one of those blades for my next riser..thnx.
Title: Re: My glue line is too noticeable..any suggestionsÉ
Post by: fujimo on February 25, 2013, 10:57:00 PM
thats if you are using a toothing plane( or similar- i like to use a saw-zall blade) and a glue with gap filling properties- then you can clamp it well-

however if you are using a titebond type glue, and a smooth mating surface- you can overclamp, and starve the joint of glue.!!!!!!

i like to use urac, and my sawzall blade- and you always get a slightly visible dark brown glue line, especially where the toothing tool has run out along the edge of the bow a bit.
but if glueing a dark wood ( like ipe) then it doesnt matter too much!
Title: Re: My glue line is too noticeable..any suggestionsÉ
Post by: D on February 25, 2013, 11:08:00 PM
I use a hacksaw blade instead of a toothing plane, or the grooves from the belt sander work pretty well.
Title: Re: My glue line is too noticeable..any suggestionsÉ
Post by: Eric Krewson on February 26, 2013, 09:07:00 AM
I always hold the mated pieces up to a light to see if I have a gap I need to work on.

If you really get frustrated with a fit you can't get right, heat both pieces with a heat gun and clamp together tightly without glue.

When they cool you will have a very good fit.
Title: Re: My glue line is too noticeable..any suggestionsÉ
Post by: CamoZ on February 26, 2013, 10:55:00 AM
Yeah, I have been using ultra bond (Canadian product made to match titebond in bonding properties). It seems to work well..it slides around very easily though. I did use a hacksaw blade to make slight grooves. They did not groove as deeply as a toothing plane would have (from my review of toothing plane results).

Thnx for the feedback.
Title: Re: My glue line is too noticeable..any suggestionsÉ
Post by: LittleBen on February 26, 2013, 02:04:00 PM
Just to reiterate what everyone here has said:

1)there shoudl be essentially zero gap before glue up.

2)roughen surface

3)even firm clamp pressure.

I find that with titebond it's be hard to overclamp using nothing but 2" metal spring clamps. They cost $.99 at lowes or HD. I have 30 or 40 and I wish I had 100.
You just cant get enough of them onto the pieces of wood to end up with too much pressure. With that said they dont have enough pressure to overcome a bad fit.

Also I find that Titebond (and presumably other water based glues) cause the wood to expand on the side it's applied to. So if you added TB to the topside of a board it would swell up slightly and be rounded on the glued side like the top of a hill.
Use this effect to your advantage, when clamping pieces glued with titebond, apply clamps to the outer edges of the workpiece. When the swelling occurs  the center area of the workpieces which is not clamped will press together firmly on its own.
I hope this made sense