How Delrin Reacts To Solvents

[jerryd6818]

Does anyone have any experience with the reaction of Delrin to solvents, such as but not limited to:
Alcohol (tried it. No go & didn't hurt the Delrin)
Mineral Spirits
Toluene (tried it. No go & didn't hurt the Delrin)
Naphtha (tried it. No go & didn't hurt the Delrin)
Gasoline
Acetone
Turpentine

I ask because I received a knife in the mail today that has some kind of silver stuff on the handles. Under magnification, it looks almost like the handles have been dipped in solder. I'm guessing that it's actually silver paint or maybe dried on polishing compound. Several trips through the sonic cleaner removed the stuff on the peaks of the jigging but I can't get it out of the valleys (I hope that makes sense). I used a toothbrush and Mothers Mag but no go. I tried alcohol, toluene and naphtha, no go.

Any ideas. I'll see if I can take pictures tomorrow.

[philco]

Jerry I've encountered a knife or two that had handles repaired with solder. Best I can recall the handes were bone. Any chance that your knife has been repaired and a missing piece of handle material replaced with the solder ?

[knife7knut]

Jerry:If it is paint and it is metallic silver;it should be fairly easy to remove with lacquer thinner or acetone. To make sure it won't attack the Delrin,I would put a small drop of the solvent on the surface and let it set for about 30 seconds.Then wipe with a dark colored rag to see if it moves and examine the scale to see if has been softened by the solvent.If not,carefully apply small amounts and wipe off until clean.To get into the jigging.go to a local auto supply or hardware store and look in their bargain tool section for a package of 3 small cleaning brushes.They usually have a steel,brass,and synthetic bristled brush in each kit. Use the synthetic brush on the scales;again just doing a small area at a time. I use them for cleaning out my striping and lettering brushes.I used to use old toothbrushes but they are not usually solvent resistant.

[jerryd6818]

Phil -- I'm pretty sure it's not solder. It just looks like it. That much solder would have melted into the handles.

Ray -- I'm pretty sure it's silver paint of some kind and for some reason. Thanks for the suggestion. I'll try that.

[orvet]

You might also try brake fluid.
Test it first but I don't think it will hurt Delrin, but it will take off paint.

[coffeecup]

I've used Citri-strip on a toothbrush to remove paint from delrin scales. Someone had spray-painted a Schrade 8OT with orange spray paint so he wouldn't loose it. It took a little scrubbing, but the paint came out of the saw marks OK. I don't think I'd try it with one of the harsher strippers like ZipStrip.

[jerryd6818]

Thanks for all the suggestions. I'll see what works today.

Thought these might help explain a little better what I'm seeing. They're not studio shots but I'm not a professional. It was worse than this when I received it but several trips through the sonic cleaner (you gotta get yourself one of those) cleaned up the high spots and a little Quick Release (thanks Scott) restored the snap. I bought it because I thought the handles might be bone but they're Delrin. Poor sellers pictures and wishful thinking. It's going to be a pretty nice user once I get the paint out of the jigging.

[reddirtknives]

I've had to use a magnifying glass and a very sharp fine pointed dental pick to remove stuff out of the jigging and scrape scrape scrape labor labor labor

[jerryd6818]

There's this problem with my vision...

I think I'm going to try something my buddy recommended today. A long bath in soapy water and then a few cycles in the sonic cleaner. What do I have to lose?

[orvet]

Not a bad idea Jerry.
I usually wash knives in warm water with some Dawn dish soap.
Then rinse them in hot water and blow dry with compressed air.

It is surprising how much gunk that will remove!

[jerryd6818]

Well, that did the trick. Soaked it in water with a little Dawn dishwashing liquid in it (in the sonic cleaner) for just about 24 hours, then ran a couple of cycles on the sonic cleaner. There was rust on the top of the carbon steel blades and the blades darkened up quite a bit BUT the silver stuff came off the handles and the rust rinsed right off the blades. Soaked the knife down with WD-40, hit it with the air hose and used some Mothers on the blades. Oiled up the joints and Ren-waxed the handles. She's good to go.

Who knew something so simple would work so well.

[CDR]

I am glad you were able to clean up that knife Jerry. In your original post you had asked about acetone. If for no other reason than posterity's sake I'll relate my experience.

About 6 months ago I unwisely used my favorite Schlieper baby butter bean to work with some models and super glue. Bad idea. Super glue coated the handles and blades.

Acetone softens super glue. Fingernail polish remover has a lot of acetone in it so I soaked my knife in it for a half hour to loosen the glue. The glue peeled right off the blades. I started scraping the glue off the Delrin scales and noticed that I was gouging the scales. As it turns out my Delrin scales were softening up and starting to dissolve. Acetone appears to soften Delrin as well.

I ended up washing off the acetone and then sanding and buffing after it dried. The handle is damaged with a few gouged out areas but the color and everything looks fine. It isn't soft anymore either. Just a little more wabi and another story to go with my knife I guess.

[jerryd6818]

CDR -- Welcome to AAPK. So now we know not to soak Delrin in Acetone. Sorry for your experience but thank you for the education.

I discovered that Goof Off contains Acetone & Xylene as the main ingredients and says on the label, "Damages many plastics, worn vinyl floors, some automotive paints and some carpets." Not "may damage" but "Damages".

[CDR]

CDR -- Welcome to AAPK. So now we know not to soak Delrin in Acetone. Sorry for your experience but thank you for the education.

Thanks Jerry.

I discovered that Goof Off contains Acetone & Xylene as the main ingredients and says on the label, "Damages many plastics, worn vinyl floors, some automotive paints and some carpets." Not "may damage" but "Damages".

Experience can indeed be a harsh teacher. First she gives the exam and then afterward she gives the lesson. No doubt, soaking in acetone = Damage!

I started off swabbing on the nail polish remover a little at a time with a Q-tip. It was really slow going and I wanted to speed things up a bit.....

I am challenged to find another like it. Ah well, I found a couple Schatt and Morgan mammoth ivory mini barlow razors for a good price. They should help me recover from my knife cleaning trauma.

Chris

[jerryd6818]

I totally understand the double 'I' syndrome. Impatient and impulsive. Gets me in trouble more often than not.

Where in Central Illinois?

Doctors orders. Take two Schatt & Morgans and call me in the morning.

Edit: If you get a few extra minutes, please drop over to the Member Introductions forum and tell us a little about yourself -- http://www.allaboutpocketknives.com/kni ... m.php?f=20

[CDR]

Champaign county a bit north and west of Champaign. This year we were surrounded by corn. Maybe we will get a little more variety next year if the neighbors plant beans in one of the fields.

[jerryd6818]

For two years we lived out in the country, just East of Sadorus. I went to Tolono High School (I think they called it Unity) my sophomore and junior years. We moved to Moweaqua over south of Decatur for my senior year. That was a looooong time ago.

[knifetime]

Jerry I have been a commercial painter most of my adult life and I have had to clean paint off a time or to.If it is paint git a product called" Goof Off "you can buy it at any Sherwin-Williams and it will not harm your knife.If it don't come off with that thin I would say it is not paint.There is 2 kinds so you may need to try both the one for latex or oil paint.Good luck it is a great knife.

[basser5]

Not a bad idea Jerry.
I usually wash knives in warm water with some Dawn dish soap.
Then rinse them in hot water and blow dry with compressed air.

It is surprising how much gunk that will remove!

A little late here as usual, but i clean all my stag this way when i get it.
It's amazing what comes off


Tim

[krayzzpat]

aye I am late here BUT I am a Electrician and I carry a Russlock for my work knife and I know for sure with those handles brake fluid, acetone, vegi oil used in transformers and keytone will make it soft and "eat" the handles. my poor work knife has seen alot of action in the field just thought this would help.

[jerryd6818]

Just in case someone runs across this six year old thread and has the same problem, I have since discovered the silver/white coating on the Delrin® handles is something I've named "Delrin® Haze" and it's very easy to get rid of. Simply dampen a cloth with some machine oil/household oil (i.e. 3-IN-ONE or similar) and rub down the handles with that. Works like a charm and it's fast. It appears that "Delrin® Haze" is caused by heat. Laying out in the sun, on the dashboard of your vehicle, etc, etc. I've even had hot tap water cause it.

[rangerbluedog]

I stole this chart from the Dupont website. They've been the primary maker of DELRIN since 1962.
DELRIN seems to resist most chemicals except strong acids and chlorine. I've seen chlorine cause oxidation in delrin, and it strongly resembles what your knife looks like, JerryD.

[Mumbleypeg]

Jerry you rascal, I started reading this thread without paying notice to the dates. While reading the first post I thought "can't believe Jerry is asking that question - must not be Delrin haze cuz he knows how to fix that."

I read down to the post by coffeecup and got excited - haven't seen a post from Jim in a long time! Then is when I looked at the date, and realized it was a post from 2012,

Ken

[rangerbluedog]

hahahahahahahahaha
I fell for the old "old thread" trap!

[jerryd6818]

Sorry about that guys. One of those rare occasions where you're better served by starting at the end and working backward.

It does have one redeeming quality though. Blue, your statement "chlorine cause oxidation in Delrin" seems to answer the Delrin® Haze mystery. I need to get some bottled water, heat it up and dip a Delrin® handled knife in it and do the same with some tap water. That should resolve the issue once and for all.