Adhesive question

[Mark J]

This seems as good a place as any to post a question or two about adhesives (if not, feel free to move it).

I am getting a lot of end grain tear out on these projects I'm doing.  Someone has suggested to me that I glue sacrificial pieces to buttress the vulnerable end grain areas.  Seems like a good idea and I have some sacrificial pieces sized up, but I am wondering about what adhesive to use?

The ideal material would hold tight until I wanted it to let go and would leave no residue. 

OK, returning to reality, hide glue (the hot type) might work, but I don't have any nor the apparatus for heating it. 

Hot melt glue is a thought and I have some, but is it a strong enough bond?  And  doesn't it leave a pretty thick glue line, so would there be that much buttresing effect?

I could go with Titebond II or III, and cut the sacrificial piece off at the glue line, but those do penetrate below the wood surface so I will have to sand a little deeper to get back to raw wood which could affect the aesthetics of what I'm doing.  

Would CA or my new favorite, DAP Rapid Fuse, stay a little more superficial?

[Chestnut]

Cremona glues cedar or another softwood on with regular wood glue and then knocks it off after he's done. The softwaood breaks away easily on the softwood side and cleans up what is left behind with a plane or sander. Make sure to put in a large enough piece so it doesn't come off with the machine operation. I don't know that no residue is possible this way.

The other option is the blue tape and super glue trick. two pieces of blue tape on each pieve with super glue in the middle. This may not support as well as the above but will remove with out residue.

[wdwerker]

I haven had any issue using RapidFuse in situations like that. I saw off the extra piece and sand but never had residual glue affect stains or finishes. I use the little bottle of the fast stuff to add sacrificial blocks. 

[RJH30518]

Using a backer board seems to be a better choice then to use glue -- which is like a backer board. Another choice would be to cut the cross grain first and then make the cut along the grain and cut off any of the tear out.

Not sure what you are building, but the idea of gluing a piece of wood to the work to get rid of tear out seems like the wrong approach.

[drzaius]

55 minutes ago, RJH30518 said:

Not sure what you are building, but the idea of gluing a piece of wood to the work to get rid of tear out seems like the wrong approach.

Not at all. Sometimes it's not practical to clamp a backer in place. A chunk of softer wood can easily be broken off & the remaining wood & glue planed off in just a few seconds.

[Mark J]

These are turned pieces so clamping something on is not an option.

Also my original post may not have made this clear but the worst tear out occurs while I am hollowing out, so along the inner surface of the pillars. 

Here twice with each rotation the tool path is perpendicular to end grain while simultaeously that section of end grain is being made thinner and thinner with each pass of the tool.  Below about 1/4" thickness the wood fractures into good sizes bits.  

Ideally to buttress these fibers you'd want something in the cut plane and just down stream exerting pressure back pushing the end grain fibers back together, but that is not possible here.  What I have done is Titebond III some cedar to the outside of the maple bowl blank.  So the butressing is now parellel to tool path and on the opposite side of the wood.  

So far the results are not very good.  But I was very judicious with the application of glue, perhaps to the point of being injudicious.  

Still I am not sure that this approach is going to work.  The sacrificial piece does not provide physical support.  It just provides a place to put glue.  I could approach this like glue sizing, but then I will definetly have residue.  

[Mark J]

I removed the sacraficial pieces, they were in the way more than they were helping. 

Yup, I was too stingy with the glue, but also where there was glue I got a very poor bond.  So the experiment was a failure, but due to the set up. 

I'll probably try this again, but Even with more glue I'm not convinced this will work.  It may just be that keeping a chamfer on trailing edge of the pillar is the best way to control tear out.