Shocking Glue Wars discovery

Sando

Sando

Knife Maker
Knifemaker / Craftsman / Service Provider
Joined
Jul 4, 2002
Messages
1,148
You know how the first glue war ended in a tie. Everything seemed to fail.

Well I did a second test on that bar and used a coarser finish on the steel (80 grit). Cleaned the bar with Simple Green, rinse, then Brake Cleaner (instead of lectra-clean).

Guess what west systems, devcon, JB Weld all came off with a push. JB Weld just fell off.

Was it stainless or what? So I redid some samples

I abraded the ATS-34 bar and glued on DEVCON, JBWELD and Gorilla Glue. No washing. Didn't touch the bar, right from the grinder to the glue

Then I made a sample with mild steel, but used Simple Green and brake cleaner. Then E-120hp and JB Weld.

Guess what? The JB Weld popped off the mild steel after the dishwasher test, but the sample on the unwashed stainless is just fine.

So........

Either Simple Green or Brake cleaner is a very BAD idea. I use alot of xylene based brake cleaner. I don't think that's it. I think it's the Simple Green. Maybe the fragrance they use ????? beats me, but I'm staying away from the stuff. (Yes I did rinse, but not very long .... evidently)

It wasn't the epoxies that failed. It was the cleaning.

The entire first round of Glue Wars meant nothing for the glues.

Steve
 
Steve, I recommended the Simple Green, and feel bad that you have wasted your time through the first round of testing because of it. My apologies.....
 
No way Mike. Simple green is famous for being a non (now we know low) residue cleaner. We learned not to use that stuff just before glue up.
 
Steve,
Thanks for the update.
More stuff on cleaning.
Unfortunately, Freon (the best cleaner ever) isn't available for cleaning, or carbon tetrachloride (a great cleaner that eats your liver).
Everclear will clean real well.
I've had problems with acetone, and it should clean well, but is a health hazard.
Lacquer thinner cleans fairly well. I use it in rod building.
If you can get 99% Isopropanol, it's a great cleaner.
This is what I use for metal and tool cleaning at work.
The 70% stuff sold everywhere is useless, as it leaves a residue...
As far as soaps and detergents: Ivory flakes or bar soap will leave no residue, as it has no lotions, moistureizers or scents - 99 44/100% pure is what is says...
I use it with distilled water on close tolerance (.00002") air cylinder piston fits, then flood with grain acohol as a drying wash, then blow dry.
Cotton disposable gloves to handle parts after cleaning and already dry.
Fingers have too much oil to get rid of, and nitrile gloves and latex gloves will always have some oil on them, as you pick them up with your fingers to put them on.
You'd have to have another person to put them on you if you don't want contamination, and then they'd have to be sterile gloves... :rolleyes:
 
Fitzo,

Don't sweat it too much. It was a PITB, but the lesson is worth it.

Howie, I sure wish you gave me a good over the counter solution! Before starting this process I read all the recommendations I could find for preparing metal for epoxies. Some of it is quite complicated and involves chemicals I don't want around.

Many of the recommendations involved an acid wash. Maybe a little scrub down with naval jelly and a rinse?

Hmmmm... Thanks for the cotton glove idea. I WILL be investing in those. A pair just for this process.

Steve
 
Hrmm, try soaking a tang in a strong ferric chloride solution till the surface is deeply etched and a little pitted, then neutralize and wash it off like you would normally, and try the adhesives.you'd have to mask of anything you didn't want to get etched as the fumes will do a job on a finished blade, but I think it might seriously help adhesion. They also sell paint-prep surface cleaner in a spray can, it's a water based solvent of some sort, you spray it on, let it sit, and then rinse with water (I'd used distilled, just to be safe) Maybe that would be better than simple green and brake cleaner, as it's made to clean a surface for adhesion for paints which in my mind are similar to adhesives.
 
tmickley said:
How do you even machine something to .00002"?
Click to expand...
very carefully :eek: it has to been done in climate controlled rooms..

direct from sanding, sand or bead blasting is best I think to stick right
:)
 
There are many products used in Autobody to clean bare metal prior to priming & painting. Some of them are cleaners and some are acidic to help stop rust. Prep-sol, can't remember if it is PPG or Dupont, works well. Spray on & wipe off. It pulls the impurities into the solvent and leaves a clean surface and evaporates quickly. Should work well with epoxy since I usually spray epoxy primer as the next step. Isn't very expensive and a gallon should last a long time just wiping down knives.
 
I don't know that you want to etch in ferric chloride as a way to clean the surface in preparation for an adhesive. Check that you don't get a layer of precipitate on the piece being etched. I always had that happen when etching copper circuit boards. One way to speed up the etching of the copper was to simply wipe the precipitate off.

Phil
 
Thanks again for the test, and the Simple Green info. I just use plain ol rubbing alcohol for the final swipe (after washing) before glueing stuff on.
 
Thanks to all of you that are taking the time to educate the rest of us! This has been an eye-opening series. I've used System Three (prolly like West) since 1982, and never a failure, wood to wood, or metal to metal (yet, my time is coming). I don't do anything special in the way of cleaning treatment, except I normally use acetone. Maybe I've just been lucky.
 
tmickley said:
How do you even machine something to .00002"?
Click to expand...
It's easy. Get someone else to do it.
It is a piston and cylinder set from a precision pressure standard.
The cylinder is closed ended and floats on a cushion of air and there are weights added for higher pressures.
It's range is .5 - 500 PSI, with the three cylinder sets of different sizes.
About .005% accuracy.
I know, TMI...

I think the metal cleaner that prevents rust, mentioned by rugerno1b, might contain zinc phosphate? The DuPont Prep-sol is good for removing waxes, greases, and oils.

Burchtree, if you can find the 99% isopropanol, instead of the 70% Isopropanol, you'll notice a big difference.

One thing I just found... If using rags, make sure they are not polyester blends.
100% cotton is the way to ge, and they can not have seen any fabric softener, as fabric saftener has silicones in it, and we know what that does under paint and glue... non-stick surface...
Howie
 
For the what it is worth department, I have never had a epoxy handle fail. What I do is use a NEW 36 grit Hogger belt and thy are rough, run the blade over belt do the same for the handle material and the pins. Put it all together and use 2 spring clamps. This has worked for a long time, when you stop to thing about it the epoxy needs something to grab ahold of. After grinding how much cleaner can you get it so why go to the trouble of using something on it that may contaminate it.
Gib
 
The most common problem with epoxy is incorrect surface preparation. Commonly people think that they are supposed to roughen the surface to get good bonding. This is NOT the primary requirement. What you do need is to get the surfaces CHEMICALLY ACTIVE, CLEAN and SOLID. What you need to do is remove any weak surface material, remove any old surface material, and get the surface chemically clean.

It may be obvious, but natural materials like antler etc. sometimes have weak material in the center where you want to do your bonding. It does no good to use 2-ton epoxy and attach it to 2-pound handle material. You may need to extensively ream out a stick tang handle and use a lot of epoxy filler to get strength in the handle. In the case of some slab handles you may need screws or rivets to provide adequate strength. The natural material may be very weak when stretched and may delaminate if secured on only one side by bonding.

Less commonly known is the need for "fresh" surfaces when you are bonding materials. An adhesive works by linking to surface molecules of the two substrates in the joint. When a surface is created by something like cutting, the surface molecules are missing neighbors on one side. The surface molecules have a mechanically enduced chemical deficiency that makes them want to bond to other substances. This is a great surface for adhesive bonding. A big issue is that this deficiency (high energy state) goes away rapidly with time. Usually within hours the surface is significantly worse for bonding or painting. In the case of rolled or forged material you don't even have a good bonding surface right after fabrication. If you cut a material with a lubricated blade you also don't initially get a clean surface. This is why people sand surfaces before bonding. You are creating a new high energy bonding surface, not "roughing up" the surface. You need to remove the entire old surface, not merely put a bunch of scratches in it. Really rough sand paper is not needed either. In the aircraft industry they often use an etching process. You need to do your surface preparation within minutes or a few hours of bonding.

Another issue is surface cleanliness. You need to use a clean volatile solvent like acetone (not oily solvent like mineral spirits) or use clean detergent solution before you do your sanding. This prevents contaminating your surface as you create it. If you use a detergent to clean the surface, rinse it thoroughly with distilled water and dry it before sanding. A sink cleanser without bleach (Bon Ami) does a good job, but be sure you do a good job of rinsing it off. Use fresh and clean sanding material and work in a clean area--really clean, put some paper down on your table. It may be optional to wipe the surface with acetone after sanding. You may just need to dust it with a clean rag. Think clean and fresh at every step. Of course you are preparing both the metal surface and the handle material surface. Both fresh and clean, clean, clean. Watch how you handle the material. You may want to wear gloves to keep hand oils off the the surfaces.

Lastly, be very careful about mixing your epoxy. Be very careful about getting equal amounts of the two components. Do not trust the dual syringes to do the job automatically. Make more than you expect to use so that proportions will be more equal. Stir the components like crazy. Transfer the epoxy away from the place you mix it before using. When I mix on a sheet of paper I scoop the epoxy to another spot before applying--the spot where I mixed it will have hardener-rich and resin-rich areas on the paper surface. Rub the epoxy into both surfaces before mating them. Save your epoxy coated mixing stick and cure it in the same area as your handle. If your mixing stick epoxy does not harden properly you know you have a problem with your finished product.
 
Good points, Jeff.
In the case of bonding wood, a freshly scraped (not a scratched) wood surface will bond better than a sanded suurface.
Sanding wood fills pores with dusts, and scraping the surface opens the grain.
Sanding to get it flat, followed by a scraper is good.
This works well on wood -wood bonding.
It should on wood-steel, also.
This should also be true for stag.
If the pores are open there is greater surface area to bond.
Any dust in pores or holes will not bond at all.
 
Scraping sounds like a good technique for preparing a wood surface. The typical recommendation is to sand and then clean off the dust using a tack cloth. This is a lint free cloth that is made tacky with something like a little bit of uncured resin like shellac. You can buy them at paint and wood working stores.
 
The trouble with a tack cloth is that it is linseed oil that has mostly dried.
Okay if you want an oil finish to follow, but not good for gluing.
Blowing off dust with a compressor is better, as it will get more of the dust out of the grain pores.
 
Mine doesn't, but it's not standard. A separator, filter, and a drier in-line...
Drying the air cuts the flow a lot, though.
 
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