If you have Goodyear welted shoes or other similar construction methods with stitched outsoles, you may still get gaps in between the welt and midsole or outsole, especially if it’s of rubber. Here I explain the reason for this, why you don’t have to worry too much about it, and how to fix it if needed.
When you buy properly constructed shoes, like welted ones, which have actual functional sole stitching made to secure the outsole, you also have to consider the fact that these construction methods in general are also made with the purpose of making the shoes easier to resole. Given this, you can’t just use the strongest glue there is, since then it may be tricky to remove the outsole when you are to replace it, even with heat or solvents.
A bespoke shoe being made with stronger (but not the strongest) adhesive on the edges and less strong adhesive in the middle, to make it easily resoleable yet relatively strong.
Therefore, manufacturers and shoemakers go for a middle way where you have something that bond well, but not too well, so to speak. Since you also have the stitching, it’s a balance that makes sense since even if the sole comes loose at the edge, it will never come loose completely. Given this, it’s common that you see these gaps in between the welt and sole, especially in the toe area where you put on most pressure and where you are more likely to get water affecting the leather structure which in turn affects the bond between the layers.
A very common sight, a small gap between welt and rubber outsole at the toe.
It’s also extra common to see on rubber outsoles, since two different materials like leather and rubber always are trickier to bond than two pieces of the same material, as leather welt and leather outsole. They also can flex and bend differently. Here balance between a strong bond and not making it too hard to remove for repair is an extra challenge. The above things are also why you often see the rubber top piece of the heel come loose as well: needs to be removable, under a lot of pressure, close to the ground where you have moist, different materials bonded.
Gaps between welt and sole can appear quickly, or slowly, often you don’t have to worry too much about it, it’s just visual. Should it open up a bit too much, it’s an easy fix though. Take them to a cobbler and you’ll have it fixed for a very small amount, or buy a good contact cement suitable for this, some popular ones are Barge All Purpose Cement, Renia Syntic Total or Shoe Goo.
Here the welt and midsole has had a gap, while midsole and outsole still is intact. All pictures: Reddit (users Knut02, yeaitsthatguy and aRandyTheMan)
Learn more about the different adhesives used in shoemaking in this article.
RE: Gap in Shoe Welt. Hi I am a construction engineer. I never knew about the weaker adhesive on the welt, but it makes sense. Could the gap also be drying out/shrinking? After wearing my leather brimmed hat in heavy rain, it is too tight on my head. Even if I dry it out slowly. I have also noticed the same phenomenon in horse tack, leather satchels and so on.
I tried an experiment on my Goodyear welt boots. The gap was welt to midsole and also midsole to sewn on rubber sole.
I put a good layer of dubbin along the gap and let it soak in. Then applied another layer. The gap went completely after 48 hours. Also my winter hill boots (after a period of no use) developed welt gaps.
Dubbed them all over and noticed the gap disappeared. So is it glue,Shrinkage or a bit of both? Steve.
Stephen Rubins: Yeah sure that’s also causing larger differences between the materials, which is why sometimes leather to leather sees less of it since it may affect more similar. Interesting you saw such large difference when you conditioned it. But yeah, I’d say it’s a bit of both.