How is Patent Leather Formed
This tutorial was created by Crystal and Glass Beads
Patent leather was originally manufactured in 1818 in just 2 colour black and white, to create the desired high gloss look multiple layers of a linseed-oil based lacquer were applied to a fine grade leather. Today the manufacturing of Patent leather used multiple layers of a type of plastic to create a wide range of coloured products including fluorescent, metallic and even two-tone patent leather items. Because the patent surface can be easily damaged care needs to be taken when preparing the surface as chemicals like acetone nail varnish remover can strip the shine/top coat of patent leather away.
How to Clean Patent Leather
Patent leather can be cleaned with a little mild soap, water and a soft cloth or some cotton wool, if the marks are a little more ground in then you can use rubbing alcohol or a non acetone nail varnish remover with some cotton wool but be aware this can also remove some of the vibrant colour from the leather. As long as the surface is clean and grease free before you start crystallizing scuff marks aren’t a problem in fact they will give the adhesive something to bond to. Generally for plastic or rubber surfaces you would scratch the surface with some fine sand paper an emery board or something similar but due to the structure of Patent leather where the plastic layer is extremely thin it’s not a good idea as you can easily damage the surface. If you intend to crystallize footwear that has been previously worn there may be black scuff marks on the leather, if soap and water won’t remove the marks you can use a rubber or as its called in the US an ‘ArtGum Eraser’. To use gently rub along the length of the scuff taking care not to rub too fast or hard or it can damage the patent coating, once the black mark has been removed you can then remove any traces of the rubber left on the leather with some rubbing alcohol (use sparingly and rub gently as it can remove the colour from the leather if the coating is damaged).
Patent Leather Adhesive Test
The three adhesives tested are E6000, Epoxy Resin (2 part) and Gemtac which according to the beacon adhesives website is supposed to provide a strong bond with patent leather. I haven’t sanded down the surface before testing because of the potential to damage the patent coating (lightly scratching/sanding down the surface of a plastic material will always provide a stronger bond than a non prepped surface).
1. Equipment used for testing how well adhesives bond Swarovski Elements with a patent leather purse, for this test we have used e6000, gemtac glue and a Multi Purpose 2 part epoxy resin.
2. Epoxy resin comes in two separate tubes, squeeze out equal amounts of the resin and hardener onto a disposable surface.
3. Stir the resin and hardener together until they are both completely mixed.
4. To apply the glue I have used a cocktail stick which I find allows you to applying / spread adhesive is small precise quantities very easily.
5. Once the adhesive has been applied it’s time to add the crystals to the epoxy resin, firstly positioning and then pressing down on each crystal so that it gets a good bonding with the glue.
How long can you work with the epoxy resin for:
You get lots of different epoxy resins some that set within a minute or two and others that take much longer to cure. Below are my observations of the epoxy tested.
15 mins – Starts thickening slightly
30 mins – Stringy if poke cocktail stick in and remove (then self levels)
45 mins - Stringy but still self levels
1hr 30 mins – Partially set
2hrs 20 minutes – Set but sticky to touch
4hrs 40 minutes – Set hard.
After a number of different tests with epoxy resin what I have found is that if you touch the surface of the glue whilst it’s tacky the surface will stay sticky even when it’s fully cured. If you leave the glue to set for 24 hours like gemtac and e6000 it’s enough time to fully cure resulting in a nice shiny surface that’s not sticky.
6. That’s the first band of crystals complete, two rows bonded with 2 part epoxy resin.
7. Next we are going to apply Rose Peach flatback crystals with Gemtac adhesive which is white when applied but dries clear and self levels which means it shrinks when curing.
8. Finally the third row of crystals which are a Pacific Opal colour are going to be applied using e6000 adhesive, which is a flexible industrial strength glue.
9. Now that the crystals are all on we are going to leave the glue to dry for 24-48 hours to make sure that they are all completely cured, (for this test they were left for 5 days).
10. SCRATCH TEST: …. Once all the adhesives had been cured I tried running my nail repeatedly over the crystals for 2 minutes on each row. I didn’t try and pick at the crystals because that’s not the purpose of the test any adhesive can be picked off if you get something sharp under the crystal. What I wanted to see was if the crystals were bonded strongly enough to the patent coating that everyday wear and tear wouldn’t dislodge the crystals. The Result was that all crystals remained securely bonded with no sign of weakness.
11. STRESS TEST: ….. To test how well the three adhesives cope with stress we are going to start from a closed position and bend the purse flap 270° then return to the starting position, opening and closing the purse flap repeatedly to simulate wear and tear through use.
12. The areas I would expect to exhibit the most stress and ultimately where the adhesive will fail first are the points indicated above which come right on the corners of the closed flap.
13. Above you can see a patent leather boot which is well worn and clearly shows the stress marks where the toe bends and the leather creases the same can be seen at the back of the shoe around the ankle area which buckles when in use. Crystallizing patent leather in an area of high stress such as the crease above would give a lasting bond no matter what adhesive you used, fortunately a purse doesn’t crease like a shoe does.
14. After opening and closing the purse repeatedly for 2 minutes everything is still secure. In daily use a purse will get opened and closed numerous times especially if you are out shopping it will also get placed into a pocket or handbag and rub or bump against other objects in your bag or pocket. To simulate this wear and tear we are now going to start rubbing a soft/medium bristle brush over the crystals to see if any of them come away this is repeated for 2 minutes (rubbing the bristles back and forth over the crystals to see if any are dislodged).
15. Another 2 minutes of opening and closing the purse repeatedly followed by using the brush is applied and everything is still secure.
16. After a further 2 minutes of flexing the purse lid back and forth you can see that the simulated usage is starting to cause the epoxy resin to break away from the patent leather surface. We are going to continue the cycle of using the brush to weaken any dislodged crystals for a further 2 minutes.
17. Now you can see that the epoxy is starting to break up from the repeated flexing and using the brush has started to dislodge the crystals on the corner. You can expect the same kind of motion from wear and tear of opening and closing the purse along with wear and tear which the brush is simulating where surfaces will knock or rub against the crystals and cause anything that’s weakened to dislodge.
18. Continuing the cycle another 2 minutes of opening and closing the purse repeatedly is carried out. (Crystals are now starting to come away on the opposite edge of the epoxy resin strip.)
19. This is followed by brushing the crystals for 2 minutes and now you can see that the gemtac adhesive is starting to loose it’s first crystal.
20. We repeated the process through another 2 cycles and the e6000 adhesive was still secure. The end result is that e6000 seems to be the most suitable adhesive for applying crystals to patent leather from the 3 glues we tested. The flexibility and strength of e6000 is what sets it apart from the other 2 adhesives, having said that I have no doubt that if I keep up the test for long enough the crystals bonded with e6000 will also start to weaken on the corners and come free.
Would I feel confident offering my customers crystallized patent leather products? Yes the bond with patent leather / e6000 and flatback crystals is strong enough that I would be confident of it holding. However if I was to crystallize a purse or handbag I would work out a design where bye the major stress points (top bend of the purse or bag) are kept crystal free this will give you peace of mind that you aren’t going to get continuous complaints from your customers.
Would I crystallize a complete shoe or a pair of DR Martens? I would have to Say no to DR Martens boots there are just too many high stress points, as regards an open pair of high heel shoes where the leather doesn’t flex that much yes I would consider crystallizing the complete shoe.
I hope you found the test useful if you have any comments please let us know and if you found the tutorial useful a like or share would be much appreciated.