Gluing The Liner

[Jason311]

All,

I have resolved this issue in my own way, but am curious as to why this is happening.

I am using hand dyed veg tan from Wickett and Craig with a drum dyed goat skin. Both pieces of leather are completely dry and I apply the cement (Weldwood) and let set for no more than 5-10 minutes. I apply this relatively heavily - enough so that both flesh sides have darkened from the cement.

I put the pieces together - use a roller pin to ensure a good fit. However, two hours later - in one case, even a day later the pieces will easily come apart.

I have solved this by simply adding another layer of cement to the one that has dried - about 30 minutes or so.

I'm curious as to why this is happening in the first place. Both leathers are highly cementable but certain liners do not stick well - both chrome and veg tan. Is the cement being absorbed by the leather and this is causing there not to be as much surface contact?

Any tips would be helpful. Thanks!

Jason

[Red Cent]

It happens quite often. If the glue looks to be dry, place your fingers on the leather. If it is tacky and not messy, slap 'em together. If very little tack is apparent, coat 'em again. I apply the glue evenly but heavy the first time. Then I grab a heat gun. Move when the glue "pimples" or glazes over.

"Is the cement being absorbed by the leather........"? Yep.

[camano ridge]

If you are using weldwood contact cement either the red or green label, you need to apply the glue then let set before joining the pieces. Apply the glue to one piece or one side then apply glue to the otherside or piece. Let sit at least 30 minutes 0or longer depnding on temperature and humidity the glue should feel dry to the touch, not wet, not tacky DRY. You should not have to add another wet coat. Now put the two pieces together press them tightly together some people use a rolling pin I just press with my fingers or palm of my hand. Now leave it alone go do something else for several hours. I preffer to let mine sit overnight. At this point everything should be well glued together. If you try to take it apart you should have to work like Heck to do so, even to the point of tearing. THe green will not be as tuff to break apart as the red lable how ever either one once properly adheared should be hard to get apart. You should not have to apply a super heavy coat. Just enough to completely cover the surface and it should be a fairly even coating on both sides. I have used weldwood on all kinds of leahter even hot stuffed leather (after ruffing the surface with a little sand paper)and never had a problem getting a good glue up. If you are only letting the glue set up for 5 - 10 minutes you are not letting it set long enough.

Edited November 29, 2014 by camano ridge

[Jason311]

Thanks for the replies - I am using the red label.

I have played around with alot of different time frames on waiting to let it set and even then it doesn't stick very well. On the other hand, I have used two types of calf skin that stick nearly immediately.

I'll keep patience in mind with this, but I was getting frustrated!

Jason

[camano ridge]

If you are using Red label it should be darn near impossible to seperate the two pieces without tearing the leather. On the label is says to let set 30 - 40 minutes before putting the pieces together. I have used it on goat skin calf skin bull hide and so on. If the surface you are gluing to looks like it has any glaze or sheen to it ruough it up a bit with some sandpaper. I have used Weldwood exclusively for better then 5 years.

[BDAZ]

I use automotive spray adhesive designed for upholstery and head liners and it works like a champ! Never had any failures including various linings including synthetics.

Cya!

Bob

[thekid77]

All,

I have resolved this issue in my own way, but am curious as to why this is happening.

I am using hand dyed veg tan from Wickett and Craig with a drum dyed goat skin. Both pieces of leather are completely dry and I apply the cement (Weldwood) and let set for no more than 5-10 minutes. I apply this relatively heavily - enough so that both flesh sides have darkened from the cement.

I put the pieces together - use a roller pin to ensure a good fit. However, two hours later - in one case, even a day later the pieces will easily come apart.

I have solved this by simply adding another layer of cement to the one that has dried - about 30 minutes or so.

I'm curious as to why this is happening in the first place. Both leathers are highly cementable but certain liners do not stick well - both chrome and veg tan. Is the cement being absorbed by the leather and this is causing there not to be as much surface contact?

Any tips would be helpful. Thanks!

Jason

Jason, I use the red label weldwood and the contact cement can be picky about temp/humidity....with that being said, I went on the suggestion of a saddlemaker who uses the stuff all the time who told me that once you've covered both pieces that are to be glued together, heat the contact cement up with a hair dryer (non sparking) just until the glue is warmed up a bit....I guaranteed you'll have to tear either the leather or the liner to get the two separated...give it a try it's especially helpful in the winter when contact cement just does not want to set at all....hope this helps

[Dwight]

Jason, . . . now I'm no expert, . . . but after about 40 years of using a product, . . . you kinda get a feel for how to use it.

Let it dry, . . . completeley, . . . thoroughly, . . . 100%, . . . dry ! Yes, . . . you can use a heat gun on it, . . . that will quicken the process.

Do not slop it on like making a peanut butter sandwich, . . . you want a thin, but even coat every where. Part of the key to that is to use a bristle brush, . . . and go back and forth over it so you are evening out puddles you made. OR, . . . try the gel formula.

The only time I have ever had it not hold to the point of tearing the leather, . . . is when I've glued the hair side. That has to be scratched up, . . . I use a wire brush, . . . and don't be gentle with it, . . . you'll never see it again once it's glued, . . . so scuff that surface really good.

Next step is to make sure the bond is made, . . . pressure is the key, . . . your hands, thumbs, rolling pin, piece of marble on top of it, . . . something to force the two pieces together. And if you can, . . . leave it for a while before you mess with it. NOW, . . . I don't do that, . . . I stick it together, . . . sand & burnish, . . . and sew, . . . then allow it to finish the bonding process after I have sewn it. My initial contact bond is always strong enough to hold it while I'm sewing it, . . . but then again that is my process.

Like it was said earlier, . . . if you can pull it apart after it was bonded, . . . YOU did something out of kilter, . . . it ain't the glue's fault.

As a test, . . . I once made a little holster for a .380 Bersa Thunder, . . . carried it for I don't know how long, . . .not one stitch in the thing, . . . only Weldwood, . . . got rid of the gun, and gave the holster to a friend. Far as I know, . . . it's still useable.

May God bless,

Dwight

Edited November 29, 2014 by Dwight

[Jason311]

Thanks for the tips guys! I'll give it a go with it dry first just to see how that goes.

[silverwingit]

I learned from a Chuck Burrows DVD (Wild Rose Trading Co.) to let the cement dry and then if the layer is not shiny, re-apply until it is. Works for me every time, no matter what kinds of leather I am cementing.

Michelle