Automotive Interior Repair with The Interior Guy

Automotive Interior Repair is an on going learning experience and I have to say that is what makes this business such an incredibly rewarding business. I just got done with another training session and would like to welcome Mark Nussbaumer with Top Grain Leather out of North Carolina to the business. I have to say this training session went really well, in fact I learned a few things from him too. He really did his research beforehand and had also attended the IICRC certification program right before coming to meet with me, which was a huge advantage, not only for him but also for me too. He opened my eyes a bit to the repair of leather and helped me to look into a few new ideas in making our repairs last even longer and the leather itself last longer too.

One of the things we talked about in our training session was the pH levels of the cleaners that I’ve been using and what it’s actually doing to the leather and the dyes and compounds as well. What I’m talking about here is the cleaners I use and the prepping solution I use to get all that grunge and goo off the seats prior to doing my repairs and throughout the repair process are really high alkaline solutions, and I mean really high, in fact the Litmus paper I used to test my cleaners turned super dark and bright, basically showing me that the cleaners are at the highest level on the pH scale. Your pH scale will run from 0-14, 0 being acidic, 14 being alkaline, and 7 being at a neutral state, which is really where you want to be. Leather should be around 7.4 at its natural state. Have you cleaned your seats before with an all purpose cleaner and when your done they feel kinda gooey and sticky like? Well that is the cleaners basically eating right through the top layer of dye and into the leather. But in most cases to get them clean and prepped to do a repair it’s almost inevitable that we use these cleaners. But again, we have to realize that what we put on leather will stay in the leather! By putting a high pH level cleaner on leather will put the leather at an imbalance state which will damage the leather. Leather is still a natural breathing skin and has to stay at a neutral state or it starts to break down, crack or even rot and crumble. So what do you do? Well I think I have the solution to the problem. After doing some testing with the Litmus papers and our cleaners we jumped on the internet to see what chemicals would lower the pH levels and keep our leather at a neutral state and believe it or not it’s the most simplest thing in the world. Something that you probably have in your kitchen already… Vinegar! Vinegar has a pH level of around 2, an acid. Which if you know your chemistry, when you mix an acid with an alkaline they cancel each other out and bring you to a neutral state. So we took a quart spray bottle and put about 6oz. of vinegar in and then filled the rest up with water. We then cleaned the a leather seat like we always did with the cleaners, tested the seat with the Litmus paper and got a reading of of course off the chart. We then sprayed the seat down with the Vinegar and water solution and wiped it down, then tested it again and the level dropped dramatically down to a reading of 7.6. Showing me that it worked, it really worked! I’m also here to tell you, you will feel an immediate difference in the feel of the leather too. No more gooey feeling! By doing this process I really think this will improve our repairs, from compounds working better, to our dyes adhering better as well. When you leave a high alkaline level like that in the leather under your dyes and repair compounds, to me your just asking for a problem. So now after every time I clean or prep in any way I neutralize after with a light mist of vinegar and water, it takes me just a second to do and that way I know I’m bringing the leather back to its natural state and if anything it’s bringing the prepping solutions back down to a level that won’t damage my dyes and compounds.

Another little trick we came up with and this was really kinda of a duh moment for me. I have been telling you all to use a fabric adhesive coated under patch on leather for holes. Well I’m here to change that, and in a big way too. What I’m talking about is something that Mark was shown in his research and training prior to coming to me. A tech had shown him where he was using thin leather as an under patch. What he had done was gone to a resale shop and bought an old leather coat for like five bucks and cut it up. Then used the leather from the coat as an under patch material. Mark was also shown how strong of a bond you will get by using leather on leather. The guy took two strips of this leather, rough side to rough side and glued them together with leather repair adhesive, set it aside for a bit to dry, then came back to and Mark said you couldn’t pull the bond apart. Of course we had to try it here, so off to leather store I went. I bought a small thin hide and also bought a scrap bag of leather which had a little thicker pieces of leather. My thinking on the thicker pieces paid off too and I’ll explain that in a minute. We took two pieces of the leather I bought and did the same test and I’m here to say you won’t break the bond, try this at home it will amaze you. I don’t know why I didn’t think of this earlier. I’ve tried this on a few repairs now and it really makes a huge difference in the bond in the repairs. I’ve used both the thick and the thin leather now and I kinda prefer the thicker leather though. The thin leather seems to bunch up and really doesn’t make for a good under patch on most of the automotive leather I’ve worked on so far. Now you don’t want something to thick that it will show through when you do your repair but thick enough it will slide nicely under the leather where the hole is. I would look for a suede or rough leather, but really any type of leather will do as long as you glue rough to rough. This little tip here I think will make a huge difference in your leather hole repairs.

One other thing we talked about, and this is one that I’ve been wanting to do for a long time now and wondering why there hasn’t been more teaching on this and that is conditioning the leather prior to dyeing. I have always wanted to find a way to condition and replenish the oils back into the leather as part of my process of repairing, resurfacing and restoring a leather seat. While Mark was in training with IICRC program, Pam Villagomez his instructor, had taught him a way to replenish the oils back into the leather by using something called Fat Liquor. What this is, is a leather softener. It coats the fibers of the leather making them more flexible which in turn makes the leather more supple and soft. I called Pam and talked with her about this and she reassured me that this is something we really need to be doing. It can be done before and after dying. So I have some coming to me and I’ll let you know how things turn out.

Well I really think these leather repair tips are going to pay off for you techs out there. So lets review a bit, neutralize your cleaners with a vinegar and water solution, use leather not cloth as an under patch when doing any hole repairs on leather, and replenish the oils back into the leather prior to dying. That ought to do it, I’ll let you all know how the conditioning before you dye works.

If you have anything to add to this please shoot me a comment. We’re all out there trying to make the best of it and any help is good help.

Talk to ya soon,
Mike Warren – The Interior Guy
Automotive Interior Professional

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