Veneer glue issues - Ultra cat

[Brian Holcombe]

Howdy,

Veneered three panels with Ultra Cat glue, mixed as directed and I put the pieces in the press for 5 hours. Completely delaminated after removal.

The glue is supposedly good for 12 mo, I marked my container when I bought it last June and have used it for a project or two in that time period without issue.

I had another container prior to this that was also junk in about 10 months, but luckily I caught when mixing rather than after gluing the panel.

I'm considering going back to better bond glue, I have projects all over the house which I've used it on without issue.

Any similar experiences or should I give Ultra cat another go?

[Jamie Buxton]

Temperature? Ultra Cat says it needs 70 degrees!

[Mike Henderson]

No experience with Ultra Cat but if I had delamination problems (glue failure) and I was sure that I had done everything right, I'd never use that glue again.

Unless you have some reason to use Ultra Cat - that it has some property that you really need - I can't see any reason to use it again.

Mike

[Max Neu]

the temperature is the big question.Those types of glues need a minimum of 70 degrees to cure right. You should warm up the substrate also, prior to gluing.I heat mine to 100 degrees for curing, the warmer, the better! Those types of glues are often used in hot presses, so dont be afraid to use heat.

[Brian Holcombe]

Every lamination I've done with Ultra cat has been at 70~, this time I actually did it outside where the temp was over 70. I dont have a way to heat it at the moment, I suppose one could use an electric blanket?

[Mike Henderson]

Every lamination I've done with Ultra cat has been at 70~, this time I actually did it outside where the temp was over 70. I dont have a way to heat it at the moment, I suppose one could use an electric blanket?
I've used an electric blanket with UF glue in cold weather and had no problems.

Mike

[John TenEyck]

I use an electric blanket over my vacuum bag to reduce cure time. Never used Ultra Cat, but if it's like other UF glues it should behave the same way, and their product brochure should list the required time/temperture. For the Weldwood Plastic Resin Glue I mostly use, it takes 13 hours at 70 F. 5 hours would be a failure for sure with PRG.

John

[Brian Holcombe]

Thanks Fellas.

i've stuck to the instructions, just a bit baffled as to why it failed his go-round. If i try the ultra cat again I think I will add a blanket and also increase the time frame.

Going for better bond on the next few glue ups...


The real problem is that I uttered the magic words of invoking Murphy's law... ' if all goes well'....when my wife inquired about when the panels would be done,

[John TenEyck]

Brain, what was your substrate? Maybe it was really porous and you didn't apply enough glue, or you waited a little too long before applying vacuum, such that the glue didn't transfer well to your veneer. I just had some seam failures and the leading potential cause of failure was that the MDF substrate that I sanded to reduce its thickness sucked water out of the PRG I used such that it didn't transfer adequately to the veneer. If your residual glue cured hard I doubt the cause of failure was old glue. It's more likely a glue transfer issue.

John

[Brian Holcombe]

John, using Baltic Birch ply. Interesting point, that may be the case here as I did not get the same amount of bleed through as I usually get.

[Keith Hankins]

I've used ultra cat for multiple laminations and never had an issue. I even pushed the 70 degree limit on a couple of occasions and never had an issue. Did you call and talk to them? Mine has set solid as a rock!

[Mel Fulks]

I think all these glues work better with thin coat on both surfaces than thick coat on one surface. Less messy ,too.

[John TenEyck]

In a perfect world I agree, but if you put glues that contain water (which UF glues do) on most veneers they will curl up and then you are cooked. You pretty much have to apply the glue only to the substrate to avoid that problem. At least that's been my experience. With epoxy you could do as you suggest.

John

[Mike Henderson]

In a perfect world I agree, but if you put glues that contain water (which UF glues do) on most veneers they will curl up and then you are cooked. You pretty much have to apply the glue only to the substrate to avoid that problem. At least that's been my experience. With epoxy you could do as you suggest.

John
I agree with that. Try waterfall bubinga, especially laid in a radial match, with water based glue. Even if you only put glue on the substrate, you probably are not fast enough to get it into press before it expands and is a mess. Waterfall bubinga is rotary cut so it expands quite a bit. But many veneers expand when water hits them, and if the panel is complex, such as a radial match, any expansion will cause wrinkles in the final product.

You just have to match the glue and your technique to the veneer. On some designs I put glue on the back of the veneer, especially around the edges, just to make sure I get good bonding in that area. But only on certain veneers, such as quarter cut walnut, which don't expand that much.

Mike

[Mel Fulks]

What veneering I have done has been on small projects ,but I have used gallons of of UF glue at one time on large
lamination projects. Also seen failures related to trying to get by with one heavy coat on large projects; once I dropped what I was doing to help an associate gluing up a large circular project when I saw he was applying glue to only one
surface. He declined my help and the lams popped loose. But subsequently he went to two thin coats and had no more
problems. As to the effect of UF glue and water I again cite the the old instructions of mfg and current advice of others to
rest the glue at least 10 minutes before applying and add the water,same as the air, needs to be warm. The difference
in how it spreads will be immediately noticed. As others have said the Unibond is superior for some jobs.

[Chris Padilla]

I think your glue expired. I really like the BB glue...never had a single problem with it.

[Brian Holcombe]

Thanks gents, I appreciate all of the insights. I think I'll change my method a bit and also at least for this project will be using BB until I decide to once again brave out UF.

[John TenEyck]

I'm curious why you would considered BB a better alternative to a UF glue.

John

[Brian Holcombe]

I am not saying it's better, I'm just defaulting to it because I'm not inclined to try UF again until I'm prepared to work out whatever kinks I've had previously. This is a full sheet of walnut that will be oil finished, no worries of veneer creep showing seams.

[Chris Padilla]

Seems the Ultra-Cat might be quite sensitive to storage time and environment. We don't know from where you hail, Brian, but it might give a clue why your year before expiration isn't quite a year. Or perhaps you just didn't but the lid on tightly? As I already stated, I've have absolutely no problems at all with BB for my veneering. And I have had it expire on me and it clearly shows that it ain't no good anymore by smelling funny, looking funny and acting funny. :)

[Brian Holcombe]

It's a bit too much quantity for how often I veneer. I have thrown out 3/4 of a container twice now.