The Crispin Colloquy

Jenny,

I've never used Soleflex but here's a tip or two for cementing rubber products:

1) rough the surcace to be cemented pretty well--create "texture' that the cement can adhere to.

2) apply a "primer" first (thin your cement with thinner to about the consistancy of water). When dry, apply unthinned cement. Cement should not be too thick--like warm honey some say. I say maybe even a little thinner.

3) allow cement to dry overnight on both surfaces. Use a hair dryer--on high...briefly--to reactivate cement (I do this on both surfaces) before attaching.

4) hammer well.

5) allow to dry and cure overnight before grinding.

Most of these tips came from Barge and Quabaug (Vibram) reps via Dick Arensberg years ago.

Tight Stitches
DWFII--Member HCC

Hey Jenny,

I had a LOT of trouble with sticking that sort of soling on some sandals that I make, but have good luck after getting a method down.

Yours looks like what mine did when I got the combo of not getting the sheet rough enough and having the glue a bit thick. When I get a good sanding and thinned cement they stick like crazy. Oh, I also rough up the leather it gets glued to.

The dry overnight before grinding is advice you don't want to ignore. (As I learned from bad experience)

Good luck.

Paul

One other piece of advice that occured to me...

It is best to cut as much of the excess off with a knife as is possible. Then, when grinding, do not allow heat to build up in any spot--keep moving and if necessary stop and let everything cool down a bit.

Too much heat will reactivate the glue and your sole will pull away at the edge.

Tight Stitches
DWFII--Member HCC

So far I've ground down the second layer of Soleflex on one shoe. Boy, was that hard to get even! I wince when I think of shoes I've had reheeled (mostly as a child) where I inspected the layers for perfect symmetry and was unhappy if I could detect 1/32" of a difference from one side of the heel to the other!

As I was grinding the Soleflex I was very fearful of overgrinding a spot. Should that happen, can you fill it with something or do you have to take that whole layer off and start over? Hoping to do the second shoe tonight.

Also hoping the layers of Soleflex stay on the shoes. Not ambitious enough to pry them off and redo them with proper cementing techniques. Figure I'll wait till they fall off, and then redo them .

Jenny

Jenny,

I think Paul hit it right on, you can use the grinding wheel you have to rough the material. It also sounds like your Barge may be getting old. When you apply it does it not want to stick to the material at first? That would be a tell tale sign. I have had some problem with Barge a couple of years back, it may have been an old can or something like that and the problem was on Urethane, not EVA. I switched to "Duall 88" and have been happy with that.
I have never worked the way DW described with the thinned down version of the cement. Normally I'm very hesitant to thin my cement as I believe it compromises some of the strength, the reps will tell you it's fine to do but I still don't like to do it. Making it as thin as water and using it as a priming layer would be different and I can see that work well.
The leather also needs to be roughed well and the grain taken off in order for the cement to get into the leather and form a strong bond.

If you take of a little to much you can just cement an other piece of Soleflex back on, no need to rip it all off unless it's coming loose anyway. I never found the need to have the work dry overnight unless you glue to something questionable such as thermo-rubber but than you will be better off using Orthec or Renia's Colle de Cologne with a primer. That said it will not hurt anything to let it dry overnight.

Just my

Rob

Hi Jenny.

I agree with everything that has been said but you may want to try using a press strap . it's just a strap sewen into a long loop thats about 2 to 3 inches wide that you can step onthe loop to apply pressure to the sole. It works really well for the arches of boots and shoes. Personally I use a heat gun from Wal-mart to heat up anything. The ones in the paint dept are much better than the others Wagner is what I prefer.....also melts the ice off windshilds nicely. ;&#62

I suspect the Barge may be old, because even when I first opened the can I found I always had to use two coats. But when you buy a can, how do you know you're getting a good one?

On the can, at the bottom of the yellow box that contains the "Directions" there are some numbers at the bottom left that include "3/05." Both cans I have, have that same number. I don't know if it's a date of manufacture or expiration, or not a date at all. Anyone know? Or can you tell by the sound when you tap the can (like a watermelon)?

re a press strap--I've seen one used, but I don't have a jack stand that would allow me to use one. I did use some clamps, but not as good, I'm sure.

Jenny

Jenny, cement rarely goes bad unless it is too thick, or thinned with incompatable thinner. Always use the manufacturer's recommended thinner. I always shake or stir my cement to re-suspend any sediment that settled in the can. It appears there may still be some "mold release" or contaminant on the surface of your sole, which caused the cement to release from the sole upon bonding, or you sanded the sole with too fine a grit paper. The sanding of the surface needs to both clean any residue off and give enough "tooth" to the surface for the cement to hold onto. I like 40 grit for rubber, but a fresh 60 grit will be ok. Lay the cement quickly and evenly so it is still fresh when it hits the surface of the materials, allowing it to penetrate. Do not rush the cement before attaching. Also a little warming (hot, but not uncomfortable in the hand) of the sole prior to applying allows it to conform better - do not overheat. If using heat to activate the cement let it cure for several hours to a day or so before attaching.
With the good advice from the above posts as well as understanding the reasoning for surface prep you should be golden for your next soling.

david

Jenny,

I had a business a few years ago where we used lots of types of adhesives and we were always testing adhesives to try to find better ones.

One thing that is crucial is that both surfaces that you are cementing are clean, clean, clean. We had precise cleaning techniques and if anyone touched the areas that were to be cemented then we would clean them all over again. Shop oils, machine oils and hand oils are adhesives enemies.

You can use an adhesives recommended solvent as a cleaner but protect yourself from fumes. I've also been told that the surface of rubber becomes oxidized and that one of the reasons to sand it is to reactivate the surface so things can bind to it.

I think that in most cases, the Barge bond to the substrate is mechanical not chemical. So DW's idea of thinning the first coat of cement to allow it into the small crevices rather than just sit on the surface is a good one and it's what I usually do. Also, sanding exposes more surface for the cement to adhere to.

You've gotten great responses to your question that I'm sure will work. Best of luck.

Tom Mickel

Jenny,

you can use a strap while sitting, you don't need a stand. You put the shoe across your legs and the strap goes around the shoe and down around one foot which is used to apply the pressure. You can hammer at the same time but don't hit the strap. If you do this with a leather sole and hit the strap it will leave an indetation on the surface.

Tim

Jenny,

Here is a photo of use of a foot strap in use.

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Tim

Sorry Jenny,

maybe this is going to work

footstrap:

Tim

Thanks, Tim. Next time I'm at the fabric store I'll buy some belting.

Jenny

Jenny, just get some yardage of nylon webbing and overlap the ends and stitch to the proper length for your lap and legs in the seated position.

Georgene

Pictures of the shoes after grinding the edges of the soles...I really butchered them in a few spots, in spite of the fact that I held the shoe with two hands and rested my forearms on the dust covers whenever possible for stability.

Here is some of the damage:


Here is how I was placing the sole against the wheel:


I had the most difficulty in the arch area because of these two curves. The grinding wheel blocked my view of how close I was to the upper.


Is using a smaller wheel or sanding drum, such as an inch in diameter, advisable as it wouldn't block the view of the work in progress?

Here are the shoes, which I'm afraid to try on!


I purchased two different shoe polish type products to try to minimize the appearance of the gouges--Lincoln Stain Wax, and something called Tarrago. Any opinions on which might be best?

Any other suggestions for avoiding grinding damage? Thanks!

Jenny

Jenny,

You'll probably get much more intelligent replies from others on this forum, but I'll stick my oar in. I have ground on non-shoe things with similar inside curves to deal with and it sounds like a multi-tool style belt grinder might be the solution you're after rather than something with wheels.

Aside from having a smaller diameter wheel to deal with the grinding surface is oriented differently so you'd be able to look down the length of the shoe at where the edges of the belt are.

You can see them here:
http://ausmultitool.com/

The downside of them is that they often run at pretty high speeds, though that's dependent on the motor you have driving it - they are designed to attach to a bench grinder.

A 2" drum sander in a variable-speed drill might do the trick too if you can anchor the drill to a bench (I just stick mine in a Black & Decker workmate).

Jenny,

The shoes are looking good, did you make the lasts too? I always recommend that you try the shoes on once the shoes are lasted and set so that when you finish them you know they are going to fit. Good luck with that.

Yes you can use a smaller wheel, I used to have a smaller one for inside waists, it will make accessing this area easier.

Another suggestion for avoiding scuffing in future is to use a rand. This keeps the sole edge away from the upper and it is easier to finish.

I will leave the polish products to others to solve for you but you could ask a shoe repairer. They generally know how to do that sort of stuff.

Resting your arms is not necessarily going to help with the grinding. You need to be fluid and finishing machines do not allow you to rest on anything.

Tim

Thanks, all. Yes, I did make the lasts. What is a rand?

I rest my arms for stability because the sanding wheel seems to want to grab the shoe and pull it out of position.

Tim, are you saying you try the shoes on before putting on the outsole? What kind of adjustments can you make at that point? And do you put the lasts back in the shoes before putting the soles on? Thanks.

Jenny

Jenny,

Congratulations on the lasts, the shoes look good from the outside.

Maybe you need to position the wheels so that they are level with your lower chest but above your waist, around the same sort of height as a finishing machine. I don't have the height with me but can find out a bit later if you like. This means that you are holding the work up to the wheels and have good control.

Yes, always try the shoes for fit before you get to the finishing stage. Just take them off the lasts and try them on. You can make any adjustments then, even rebuild if necessary without having to destroy a completed shoe. Then you put the lasts back in and finish them.

A rand is an imitation welt strip. It is bought in rolls or cut to length. I will find a photo for you and put it on soon.

Tim

Jenny,

All beginners have problems with grinding soles. My daughter built a pair of boots with me some years ago. They turned out really well...until...until she went to shape the heel. And on the medial side (where the arch is) she slipped and tore up the arch area of the boot. She was devastated. Much larger area of damage and much deeper than your example.

It all comes down to time in the saddle. With enough experience and a fair number of dings and other mistakes to make you cautious, you'll stop doing this.

I do agree with Tim when he says that bracing your hands against the framework is only going to make things worse.

Also you might need to raise the level of your wheels. Mine are about waist high...maybe a little higher but I can lean over a bit and see the wheel where it touches the sole...even in the arch area...so I can control and anticipate problems before they happen.

But my arms are bent at the elbow and there is a natural comfort at that height.

And if your wheels are not at the edge of the bench...even hanging over the edge...they should be.

Hope that helps some....

Tight Stitches
DWFII--Member HCC

(Message edited by dw on June 05, 2007)

Practice certainly doesn't hurt! I did a little better on the second shoe than the first.

Took a deep breath and tried the shoes on last night. They are too loose, which I was half expecting. I had remade the lasts and knew I should have made some fitter shoes first, but was too impatient. Live and learn!

I made the topline lower at the back of the heel than the first pair, and this pair slips at the heel. Partly, I think the wedge sole being stiffer is contributing to this. I can see that it will be tricky to make the heel area of the shoe fit in such a way that it will not hurt the tender area of my heel at the topline, and yet be snug enough to not slip. The first pair were high in the back, didn't slip, but hurt.

Back to work on revising my lasts tonight! If I ever get them perfect I'm going to have to make several pairs of duplicate lasts and stash them all over the world, so no matter which house burns down or which continent explodes, I can always retrieve a pair of the lasts

Jenny

Jenny

Have you thought about using a Padded Collar around the heel and quarter? I know it works really well for my work shoes. Just a thought, Joel

PS: Shoes and Last look nice!

Joel, it would be tricky, but I'm not ruling it out! I've tried on only one pair of casual shoes at a store with a padded collar that felt OK. But the padded collars on athletic shoes are usually not comfortable for me. At some point I may experiment with that, though, if all else fails.

I am toying with the idea of putting a layer of elk skin inbetween the shoe's lining and the counter. I'd prefer to not have to do that either and will try at least one, or may two more times to get it right by adjusting the lasts, first!

Jenny

Jenny,

As you have a soft sole, you can bend the shoe at the forepart by hand to start the flexing process. The wedge being stiff is as it is supposed to be, only the forepart flexes.

What is the problem with your heel? Is it a spur or sore tendons? This seems to be the first thing to sort out and may give someone a better idea of how to help.

Tim