Glue Up Gaps?


jahill5

Recommended Posts

Hey Guys,

 

I'm looking for some advise/opinions.  I'm face gluing two pieces of 8/4 Maple together to create a turning blank for a rolling pin.  During my dry clamp up, I noticed I have some small gaps. My feeler gauge gives me .0039 inches (.1 mm). I usually glue up with Titebond 3. I'm worried that I'm going to end up with cracks in my finished piece where the gaps were.

As background info, the boards were surface planed to thickness, and the few planer nick lines were cleaned up with a card scraper.I have a couple blanks to glue up, and each one seems to have this small issue.

My current idea (I only really have one) is to switch to epoxy for the glue up, in order to have a gap filling adhesive.

I'd appreciate some feedback, and ideas.

 

Joshua

IMG_20181201_212323.jpg

IMG_20181201_212345.jpg

Link to comment
Share on other sites

I would try to flatten the pieces more before glue up.  You might try placing a sheet of sandpaper on a flat surface like a cast iron table.  

If this is as good as it gets then I would go for it.  Epoxy is probably a better choice.

I guess I have some concern that since the item will be periodically washed the glue joint might widen.  But maybe I'm making that up.

It will look better for what I assume will be gifts.  

One final thought, just to add more work to your to do list, slip in a thin piece of contrasting wood.  That way you'd have two glue joints to figure out :) (but it would hide any gaps you can't get rid of).

Link to comment
Share on other sites

10 hours ago, jahill5 said:

the boards were surface planed to thickness

If the gap is just at the ends of the pieces, I'd suspect snipe at the ends from your planer.  You could hand-plan e them to get a better planed surface; I really like the idea above of using a piece of sandpaper on a flat paper and lapping/sanding against that, to get a dead flat surface; or (the usual approach to snipe) joint longer pieces, and then cut the ends off.

  • Like 2
Link to comment
Share on other sites

Ok so... Moving forward here. I'm gluing some sandpaper to a piece of glass and I'm going to attempt to clean this up that way first. Depending on the results, I may still go with the epoxy glue plan.

As much as I'd like to start modifying the project, the glue up is the only part of this one that is actually mine. The rest is the Wife's project, so I'm going to refrain from making changes.As there are a few of these to do (Yes she's making Christmas gifts) I'll post results after this next one.

  • Like 1
Link to comment
Share on other sites

Echoing John Fitz, this looks like planer snipe. My little cheapo does it, too, and I've gotten accustomed to starting with boards that are 6" overlength and then wasting off 3" from each end.

If you're already committed to these boards as is (and Christmas is just around the corner, so I'd understand) then I say just glue them up and go for it.

  • There's a vast field of gluing surface elsewhere in the blank, so this is not a safety hazard that will blow apart at speed on the lathe.
  • This being at the end of the board, you're going to turn this section down to a much narrower diameter than the rest of the piece. That deep into the blank, the glue will have completely filled the gap.  (Out towards the edge, not so much) Give it a little extra time for that thick glue joint to fully cure and go for it.

The glue line in the handle ends will be a little more visible, but the rolling pin recipients will still be delighted.

  • Like 1
Link to comment
Share on other sites

+1 on snipe. I usually mark the faces from my joitner to get glued together and try and leave the planer sides outward. If i need to glue both sides i take a light pass with my jointer after i have everything parallel to ensure that it's perfectly strait.

I don't think it'll cause a problem as far as seperating.

Thinking out loud if the crack could be filed with CA glue and then sanded back prior to finishing. This would at least fill the crack so flour and dough doesn't get in there. Epoxy is another option but will probably be far messier. The crack is less likely to get noticed if you can't feel it or get a fingernail in it.

Link to comment
Share on other sites

I had the same problem when gluing up the 8/4 boards for my Morris chair.  The boards looked flat, even with a straight edge, but when clamped up the gap was visible.  I spent forever re-jointing, re-planing, and sending the boards through the drum sander.  The chair is done now and there are no gaps, but this was the #1 reason I scrapped the through tenons...the gap was too visible in the tenon. 

It seems that gluing up thick boards keeps you honest and exposes minute snipe and jointer/planer inaccuracies.

Link to comment
Share on other sites

  • 3 weeks later...
  • 2 weeks later...

One quick suggestion for future lap sanding exercises - clamp the two pieces to be sanded together so that the surfaces to be glued are both sanded at the same time.  That way, if they aren't perfectly square they're at least in the same plane and will mate properly for glue up.  This trick can and often is also used when planing a joint.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.