How to glue rubber to leather

[deboardp]

I'm making a four sole sandal, three layers are leather, glued and stitched together. The fourth layer is 1/8" gum rubber, a full sole. What's the best glue for this? In my glue drawer I have Barge, Renia Top-Fit, Renia Aquilim 315, and Intercom Ecostick 1816B. 

The last one listed holds great when dry but the leathers separate when wet. They can be pulled apart. 

The shop is in my living room so i haven't done that experiment of soaking and pulling apart with the other glues. I'm thinking the water based glues will also not hold when the leather is well soaked but that possibly the barge will hold. Anyone know? 

The leather will be well roughed and the rubber, too. I have a one ton manual press for some pressure on it. 

Edited December 27, 2023 by deboardp
Sp, details

[Hags]

I tried the water based glues. Not as good for holsters.  They seem to not hold very well when wet molding. I went back to weld wood contact cement. We also used the rubber cement on conveyor belts in industry. I'd use the Barge.. Do it outside if you have to.

Edited December 27, 2023 by Hags

[deboardp]

I'll use the barge. I bought a twin fan window unit, reversible air flow, and put it in the shop window, blowing out, and I open a window in another room.  

[DieselTech]

Try some of this epoxy. It's a 24 hour slow cure flexible epoxy & is good stuff for bonding about anything. Rough your leather & rubber with 80 grit sand paper. 

Then apply a thin layer of epoxy to your rubber & to your leather. Then weigh your project down to cure over night. 

This epoxy goes a long ways & dont take much. 

It has a very mild odor too.

[Mablung]

46 minutes ago, DieselTech said:

It has a very mild odor too…

…giving it a considerable advantage, as far as pleasantness to use, over Barge and Tanner’s Bond. May have to try that stuff out once I run low on Tanner’s Bond. 

[DieselTech]

31 minutes ago, Mablung said:

…giving it a considerable advantage, as far as pleasantness to use, over Barge and Tanner’s Bond. May have to try that stuff out once I run low on Tanner’s Bond. 

Yeah it's worth trying for rubber to leather. That epoxy has a un godly shear & holding strength. It's slow curing so you got lots of time to work with it. It takes about 12hours before it starts to set. 

It stays extremely flexible in thin layers/application, yet has unholy pounds pre square inch holding ability. 

Edited January 25, 2024 by DieselTech

[Dwight]

4 hours ago, DieselTech said:

Try some of this epoxy. It's a 24 hour slow cure flexible epoxy & is good stuff for bonding about anything. Rough your leather & rubber with 80 grit sand paper. 

Then apply a thin layer of epoxy to your rubber & to your leather. Then weigh your project down to cure over night. 

This epoxy goes a long ways & dont take much. 

It has a very mild odor too.

My heavens and OUCH . . .  have to wait until I sell some more stuff before I can order it . . . 

May God bless,

Dwight

[Tastech]

May i offer my advice . As a shoe maker and repairer i glue rubber to leather all day every day . Its no big deal . Any contact rubber cement will do the job but some are much better than others . I use and recommend Renia Colle de colonge  .Apply on both surfaces and let dry for about 30-60 mins . With a heat gun or even a blow dryer heat the rubber piece then apply to the leather . Cut the rubber larger than the sandal and trim the rubber with a knife . At some point you are going to have to replace the sole  so you heat the rubber again and with pincers remove the rubber and replace . Using epoxy is not an option because it is brittle and will crack even the flexi stuff and will do damage when trying to replace the sole  , Also you have to keep the sandal in a press for 12-24 hours . Another option is to use a product called shoe goo . It is flexible but needs to be pressed as it is not a contact adhesive . I use shoe goo mainly for hiking boots especially the toe piece that returns upwards . To keep it in place i wrap a cut down bicycle tube around the shoe for a day or so . Either way contact adhesive is the best option . Yeah its a bit wiffy but so what  only smells for about 10 mins  and it wont kill you . I would also recommend you get proper sole rubber from a cobbler as it has a different composition than regular rubber and comes in an assortment of treads .

[Tastech]

the sole rubber from cobblers comes pre roughed on the glue side to make the glue stick to it  . rubber that has not been roughed can come unstuck

[deboardp]

1 hour ago, Tastech said:

May i offer my advice . As a shoe maker and repairer i glue rubber to leather all day every day . Its no big deal . Any contact rubber cement will do the job but some are much better than others . I use and recommend Renia Colle de colonge  .Apply on both surfaces and let dry for about 30-60 mins . With a heat gun or even a blow dryer heat the rubber piece then apply to the leather . Cut the rubber larger than the sandal and trim the rubber with a knife . At some point you are going to have to replace the sole  so you heat the rubber again and with pincers remove the rubber and replace . Using epoxy is not an option because it is brittle and will crack even the flexi stuff and will do damage when trying to replace the sole  , Also you have to keep the sandal in a press for 12-24 hours . Another option is to use a product called shoe goo . It is flexible but needs to be pressed as it is not a contact adhesive . I use shoe goo mainly for hiking boots especially the toe piece that returns upwards . To keep it in place i wrap a cut down bicycle tube around the shoe for a day or so . Either way contact adhesive is the best option . Yeah its a bit wiffy but so what  only smells for about 10 mins  and it wont kill you . I would also recommend you get proper sole rubber from a cobbler as it has a different composition than regular rubber and comes in an assortment of treads .

This is good news! 

Can I bother you for links?

For the Renia Colle de Colange? I couldn't find the receipt for the other Renia product I have. 

For the cobbler who sells(you) sole rubber? I couldn't find the receipt for the gum rubber I have, either. Is it crepe your talking about? I'd prefer something thinner and harder. I also bought some

I bought a sheet of gum rubber last year and have built my first sandal. I'm ready to stitch the three layers of leather. I'm still pondering a heel of tougher rubber as I'm assuming the heel will wear the fastest. I did buy some Goodyear Neolite heels in various weights and would like to use the thinnest one I have, 12 iron, for the heel. I hadn't made a decision on it because I didn't know how to glue it on. On the side of the heel it says 17/18 (my gauge confirms 17.5 ounces), 12I, W-4103, and SSI. This is a stiff piece of rubber. The gum is flexible. The tri- layer leather soles are stiff, too. I had been concerned that the wearer would feel gravel through them but now I doubt that. Now I'm concerned that they will be too stiff to be comfortable but also think they might loosen up, especially if I hand stuff some grease into the topsole. All three layers are 7/8 ounce, as well as the straps. All are firm HO veg tan

except the straps and midsole which are Tandy utility grade veg tan, a very nice side, only $129!