What Does it mean?

Thanks

it means that in your computer's file system, lets see, how to simplify this.... say you have file A, it consists of several clusters, the smallest unit of storage for data on your disk. think of boxes full of parts from your chevelle tear down. In the file system is a list of the address of all the clusters that make up file A. Like a list of the contents of all the boxes that contain the interior trim etc..etc... In your case both file A and another file, lets say B, contain an address of the same cluster, which is impossible, since files cannot share clusters. kinda like the box of interior trim will not also contain engine parts, therefore should not also be on your whats in the boxes parts list as going with the engine parts.

run scan disk and defrag your computer from the system tools utility, it attempts to correct lost, cluster that are no longer listed in the file to which they belong, and cross linked files. Defrag will then clean up your disk, that will help your computer to keep better track of your clusters.

hope that makes sense. It is easier to explain in person when I can draw the thing on a black board :D

Originally posted by deiinc:
What Does it mean?

Thanks

To me crosslinked is when two different chemicals combine to form one NEW chemical.
Think of water. 2 atoms of hydogren link up with 1 atom of Oxygen
Modern clearcoats, primers etc crosslink, the clear crosslinks with the hardner thus forming a new product

Sevt, yours is the definition I had in mind also since this is the body/paint forum.

crosslinking was explained to me by a PPG rep. He said picture a fresh coat of paint or clear wicking into the substrate (primer,sealer,basecoat) or being partially absorbed by the substrate, then the solvents are released back through the fresh coat of paint. When the solvents wick in they pull a small amount of paint into the substrate and when the solvents evaporate back out they pull a small amount of the substrate into the fresh paintor clear. The end result is crosslinking. Although the majority of primers and sealers used today are not considered soluable products they do soften when exposed to urethane type reducers indicating that some absorbtion takes place. Most basecoats are very soluable enabling the solvents within the clearcoat to penetrate, many basecoats can be activated with a small amount of clearcoat hardener to help the crosslinking process. Activated basecoat helps durability especially when many coats of base are applied like in tricoat colors. The activated basecoat almost becomes one with the clear and is less suseptable to rockchips etc., Activated base does not spray as well as nonactivated. Bob

Bob, your PPG rep was wrong. "Crosslinking" is exactly what Eric said it was. Well sort of, the water is a bad example. It is the linking of molecules to form a new compound. Urethane clear does this in the cup after you spray it, as well as the film on the car. It becomes a new compound.

Where, Lacquer doesn't do this. It could theoretically be scraped off the car and put in a can with thinner, shaken up and reused. Anything that has "crosslinked" couldn't do that.

This of course doesn't mean that the rep wasn't "sorta" right. smile.gif If the base has hardener, and the clear has hardener they will "crosslink" together. What he was refering to is more of a "coheasion".

Click here for "Crosslink page" (http://www.psrc.usm.edu/macrog/xlink.htm)

Thanks Guys. I was asking because some of the PPG tech sheets that I have been looking at mentioned crosslinking.

man, was I way off on that one. I'd never heard of cross linking outside of the computer world. I learn something new every day here. You guys are the teacher, I am definitely the student in this arena. I didn't even give a thought to the fact that the question was in the body forum....

oh well. you should scandisk and defrag your computer just to make me feel less stupid graemlins/clonk.gif

Originally posted by Professor_SS:
man, was I way off on that one. I'd never heard of cross linking outside of the computer world. I learn something new every day here. You guys are the teacher, I am definitely the student in this arena. I didn't even give a thought to the fact that the question was in the body forum....

oh well. you should scandisk and defrag your computer just to make me feel less stupid graemlins/clonk.gif Hey, don't feel stupid, I now know who to ask when this darn puter messes up. I don't know a single thing about it! ;)

Yeah, Professor! While you are here, how about 'splain' that degrag and scandisk thingie.. smile.gif

scan disk attempts to restore file links and checks the surface of your disk for bad spots, like pot holes and puts road cones in front of them so your computer doesn't try to drop your data in one, and defrag re-arranges all of your data into nice contiguous strings so that the computer can find them easier, often speeding up your machine and reducing lost and cross linked clusters. Both programs can be run from a command prompt or via system tools.

jeez, I still feel dumb. I have listened to you guys saying never ever mix products so much, and I believe damn near everything you guys say, :rolleyes: that I never even thought about mixed chemicals/paints when that crossed linked question came up graemlins/clonk.gif

Originally posted by vettefella:
Yeah, Professor! While you are here, how about 'splain' that degrag and scandisk thingie.. smile.gif

Originally posted by Professor_SS:

jeez, I still feel dumb. I have listened to you guys saying never ever mix products so much, and I believe damn near everything you guys say, :rolleyes: that I never even thought about mixed chemicals/paints when that crossed linked question came up graemlins/clonk.gif

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Just so we are completely clear on the subject, "crosslinking" is a good thing and intentional...not in the context of mixing different products or brands of paint. It's a chemical process that takes place when one product is added to another and a completely(chemically speaking) product results. For example: adding hardner(also referred to as catalyst in the chemical world) is added to clearcoat. Check the definition of catalyst and see what I mean.

Years ago(early 80s) Rinshed-Mason(R-M) paints had a product on the market to be used in their enamel paint enhanced with acrylic that they called "Crosslinker". It was a kinda-sorta catalyst that caused the paint to kinda sorta emulate acrylic enamel, but not really. smile.gif That was my first exposure to the term "crosslink".

FWIW, if you never had the displeasure of shooting R-M's so-called acrylic enamel paint with or without the crosslinker, you escaped a unique experience. It required a spraying technique like no other kind or brand of paint.

A crosslinked polymer be would polyester resin used in fiberglassing.
A noncrosslinked could be something like parafin wax.

The PPG rep explained it as a reaction between two layers of applied finishes not a reaction of two components mixed together. As in clearcoat applied over basecoat and the reaction between the two layers. I guess I learn something new everyday, that's a good thing. smile.gif

Badbob:

I don't think your PPG rep did you justice with that explanation. Cross linking is the chemical joining of two different polymer molecules, either with themselves or a cross linking agent. Natural rubber (latex) is crosslinked with sulfur to produce hard rubber. Golf ball covers are acrylic acid coplymers cross linked with zinc or calcium ions. Polyurethanes are polyglycols crosslinked with di-isocyanates. It is doubtful that a clearcoat would react to crosslink with an already hardened substrate. There is certainly covalent bonding between clear and base, but this is an adhesion phenomenon, not cross-linking. All thermoset resins are cross linked.