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david babcock
01-24-2008, 1:41 PM
After reading for a half an hour I just need to ask for some help from the pros.

I am gluing up four 1.5 x 54 inch slats to a very gentle curve (sleigh rail on crib). I have very small gaps at the curve from the table saw not cutting the 6 degrees precisely. The boards come together nicely but im worried about smoothness.

Which glue is going to be best for luting and finishing very small gaps in this arch?.

thanks everyone!

Joe Chritz
01-24-2008, 1:48 PM
None of the PVA (yellow) glues fill gaps very well. For gap fill it is almost certainly some form of epoxy that is needed.

You can occasionally use PVA glue mixed with sanding dust to create a gap filler of sorts that works to different levels.

Somewhere I have a wood rag that did a strength test of a bunch of different PVA glues. With some very minor differences they were all pretty much the same and much stronger than the surrounding wood.

For lots of individual spindles (ala-mission style headboard) I generally use elmers white school glue for a longer open time. It can be a bugger to get all those spindles in the right spot. Now there are glues specifically designed to give longer open time.

Joe

Sam Yerardi
01-24-2008, 1:48 PM
I've had good luck with both yellow glue and hide glue. Hide glue was used for the ribbing on lutes so structurally it is a sound (no pun intended ;)) approach. I don't think hide glue will bridge gaps as well as yellow glue but others may have had better results than me. Both of these glues should work well from a finishing standpoint. If bridging the gap is a greater issue then epoxy might be a consideration.

david babcock
01-24-2008, 1:56 PM
wow, this is my first post here after reading for months.
thanks for the speedy replies. I bought some tightbond III at the recommendation of a friend at the local hardware store. My gaps are not significant- I will snap a picture.
ps im using white oak (dont know if this matters).
http://www.sawmillcreek.org/attachment.php?attachmentid=79999&stc=1&d=1201202031

http://www.sawmillcreek.org/attachment.php?attachmentid=80000&stc=1&d=1201202031

glenn bradley
01-24-2008, 1:57 PM
Depending what you mean by 'small gaps' PVA will fill-in a bit. As Joe points out, PVA will not fill larger gaps. Even in a 1/16" gap the glue will shrink and have to be reapplied to fill which is "just wrong" IMHO. If your gaps qualify as a bit larger, the sawdust and PVA mix can work aesthetically. If you are looking to fill and provide structural function, I would go with epoxy. Either will be a bit of a finishing challenge depending on your finish.

glenn bradley
01-24-2008, 1:59 PM
wow, this is my first post here after reading for months.
thanks for the speedy replies. I bought some tightbond III at the recommendation of a friend at the local hardware store. My gaps are not significant- I will snap a picture.
ps im using white oak (dont know if this matters).

TB-III dries dark and will contrast with your white oak strongly. TB-I dries almost white and can be just as bad for that reason. TB-II dries an ivory-leaning-toward-yellow color that is easiest to hide for me, FWIW.

david babcock
01-24-2008, 2:21 PM
TB-III dries dark and will contrast with your white oak strongly. TB-I dries almost white and can be just as bad for that reason. TB-II dries an ivory-leaning-toward-yellow color that is easiest to hide for me, FWIW.


Glenn,
Im planning on staining the project a very dark walnut/mahog color- will the color still contrast? You've got me worried about color also now!
The gaps seem smaller than 1/16 (the end photo looks larger because it is not clamped).

Sam Yerardi
01-24-2008, 2:24 PM
I would try Franklin's Liquid Hide Glue. It will dry to a color that will work with walnut.

david babcock
01-24-2008, 2:24 PM
None of the PVA (yellow) glues fill gaps very well. For gap fill it is almost certainly some form of epoxy that is needed.

You can occasionally use PVA glue mixed with sanding dust to create a gap filler of sorts that works to different levels.

Somewhere I have a wood rag that did a strength test of a bunch of different PVA glues. With some very minor differences they were all pretty much the same and much stronger than the surrounding wood.

For lots of individual spindles (ala-mission style headboard) I generally use elmers white school glue for a longer open time. It can be a bugger to get all those spindles in the right spot. Now there are glues specifically designed to give longer open time.

Joe


Sam/Joe,
are my gaps significant enough to require epoxy? Im no pro like you guys- i just need something to keep the curvature smooth and stainable. :)

glenn bradley
01-24-2008, 2:45 PM
Glenn,
Im planning on staining the project a very dark walnut/mahog color- will the color still contrast? You've got me worried about color also now!
The gaps seem smaller than 1/16 (the end photo looks larger because it is not clamped).

You're in luck as you already have the TB-III. Take a small piece of scrap and drill a small hole in it or cut a small notch with a chisel. Drop some TB-III in there and let it dry for 24hrs. Hit the scrap with some of your stain and see how obvious the TB-III looks.

I am a big fan of test-blocks for finishes. I sometimes run a half a dozen samples before I decide on my finishing regiment. After all the work I've put into a piece, I figure its worth a little more effort to make sure I don't get surprised by the finish.

In your clamped pic I don't see that the gaps are much to be concerned about. They should fill fine with your glue. Even if there are color deviations, those gaps (when clamped) are small enough that I would think they'll blend in with the joint and the grain patterns. Just my .02.

david babcock
01-24-2008, 2:50 PM
You're in luck as you already have the TB-III. Take a small piece of scrap and drill a small hole in it or cut a small notch with a chisel. Drop some TB-III in there and let it dry for 24hrs. Hit the scrap with some of your stain and see how obvious the TB-III looks.

I am a big fan of test-blocks for finishes. I sometimes run a half a dozen samples before I decide on my finishing regiment. After all the work I've put into a piece, I figure its worth a little more effort to make sure I don't get surprised by the finish.

In your clamped pic I don't see that the gaps are much to be concerned about. They should fill fine with your glue. Even if there are color deviations, those gaps (when clamped) are small enough that I would think they'll blend in with the joint and the grain patterns. Just my .02.

Glenn & all, thank you so very much for your time. Im behind the gun on this crib with our first little one due march 17th. Good call- I will test the couple stains we are looking at. PS, will I lose much in quality or bond strength if I decide to go back to TB II?

Sam Yerardi
01-24-2008, 7:40 PM
Based on looking at the pictures, and given the application, I would lean towards the epoxy route for a couple of reasons. It is my opinion that you have a little more flexibility in coloring the epoxy than you do with anything mixed with PVA. Another reason is that one of the criteria for a good solid joint is not only the glue but the mating of the surfaces. The less mating, the weaker the joint. Epoxy bridges that as long as you know you have penetrated the gap as much as possible. PVA's will tend to 'shrink' up to the surfaces they are applied to and not maintain 'bulk' in the open spaces. Again that depends on the size of the gaps. I'm trying to judge by looking at your pictures and they seem large enough that I would go with the epoxy. The application is what is mainly driving me to this conclusion.

david babcock
01-25-2008, 1:27 PM
OK i glued up two small pieces cross-grained and stained with two coats of varathane. The lines barely show up against the grain and I think that they will show up even less when they are running parallel with the grain.
As for gaps- the boards match up nicely- its just at the top there is a 1/32 gap 1mm deep from some small tear out that I think will be filled and or sanded smooth when I sand out the arch...

Sam Yerardi
01-25-2008, 1:30 PM
Looks good - what kind of glue did you end up using?

david babcock
01-26-2008, 1:52 AM
Sam, this was just a test with the TB III that I already had. Im going to test a larger section with the grain running the correct way also.

david babcock
01-26-2008, 2:00 AM
Sam/Glenn/JOe,

So ive been looking for 1.5 or 1.75" oak dowell with no luck at all.
BUT a local hardware store had some handrail at 1 3/4 so i decided to try it out for the rail on the crib.
Problem is- it is not completely solid. It is a large piece joined together in several sections of different shades with little finger joints.

QUESTION: from your experience will these different shades of the same oak stain differently enough to stand out from one another (i intend to stain it quite darkly)?

Doug Shepard
01-26-2008, 8:08 AM
Sam/Glenn/JOe,

So ive been looking for 1.5 or 1.75" oak dowell with no luck at all.
...

One of Amazon's sellers seems to have some.
http://www.amazon.com/Oak-Dowel-Rod-36-Restorers/dp/B00093DHVC
I'm sure there are others. This is just the first one than panned out when I googled. Didn't try searching on the 1-3/4 though.

david babcock
01-26-2008, 10:22 AM
One of Amazon's sellers seems to have some.
http://www.amazon.com/Oak-Dowel-Rod-36-Restorers/dp/B00093DHVC
I'm sure there are others. This is just the first one than panned out when I googled. Didn't try searching on the 1-3/4 though.


yea, I tried emailing them - and subsequently the next 29 webpages I saw on google, but none have a dowel at least 54 inches long.
Thats why I finally resorted to this dang handrail after two weeks.
I literally emailed or phoned thirty companies rockler, cincinati, caldowel, woodnshop dowel, excel dowel etc etc. :(

Doug, so what do you think about the difference in shades?