Cross Hatch Adhesion Test

[Mac Simmons]

I do not understand why this "message board" is not being fully used?
It is just a great way to look for finishing information, and to learn how others do things.

I hope this get's things going again.

Do any of you do, or know some one that does the "cross hatch adhesion test" on their finishes?

I would like to know how long you or they allow the last to dry / cure, before doing the "cross hatch adhesion test?

MacS

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[Shane Watson]

Hi Mac!

Hows things over in the good ole US of A?

I did this test years ago to help me decide what finish to use on my work. I took several of the different finishes and brands and coated sample boards to each finish's specs.

I did two samples of each and left one to cure overnight and the other to cure for, I think it was two weeks ( can't really remember been awhile http://ubb.ubeaut.com.au/ubb/smile.gif )

Anyway, preformed the tests and compared results with the second samples and chose the best result for the lacquer I still use today. Of course if my clients wants me to use another finish, I do.

I did the stupid thing of not writing down my results. As at that stage I was really only doing for self satisfaction/interest.


Cheers

Shane.


[This message has been edited by Shane Watson (edited 21 May 2000).]

[Chris Longworth]

Hi all.
This may appear to be a dumb question?
But what is a "cross hatch adhesion test".
Regards.
Chris

[Mac Simmons]

HiShane,
Things are going well over here.
How are things going for you.
I thought I would try to get the board going. It really is a shame that more finishers are not using it.

Chris,
The test is used to check the adhesion of the coatings to the substate (wood)

The test is very simple to do.

A piece of masking tape is place on the coating.
A "cross hatch" is cut into the tape.

( a "cross hatch" is a pattern that is used when playing the game "Tick Tack Toe")

The tape is pulled off, and if any of the coating lifts off with the tape, then a determination is made according to how much of the finish was removed.

The test is used after finishing new work, after refinishing, and when mixing different coatings to do a finish,the test will let you know how good the "bonding of coating and the wood" really is?
It is a do-it-yourself test just like the pencil hardness test.

MacS

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[RFNK]

Ummm..., you put a bit of tape on the finish and then you peel the tape off to see if any finish sticks to the tape? What's the cross hatch for? Is it cut right through the tape? Rick aka Dopey

[Chris Longworth]

Thanks Mac for the explination.
Chris

[Mac Simmons]

Rick,
The knife cuts through the tape into the finish.
If the adhesion is not good, the tape will pull the finish some off.
If the adhesion is good, the finish will not come off.

Thank you, Chris.

MacS

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[This message has been edited by Mac Simmons (edited 26 May 2000).]

[macka]

I have carried out this test many times and have always cut the finish ie cross-hatched first and then applied the tape.The tape is then quickly peeled back and the corners of the cross-hatch examined for any peeling or delamination of the coating from the surface or the previous coating.This test will tell you whether the coatings are compatible or if the sanding and preparation was correct.
Tks for the opportunity to reply
Cheers

[MacS]

This is late, but better late then never. Maybe, others will benefit from it.

Here is an article that explains the "cross hatch test."

http://iswonline.com/ArticleLanding/tabid/67/Default.aspx?tid=2&heading=Fundamentals%20of%20Finishing&modid=520&ContentID=9340

[astrid]

MacS
why are you posting threads to answer them yourself ?:?

Astrid

[MacS]

I just ran across this thread while doing an on-line search, I thought, I would post this article to explain how the process is done.

There, maybe others looking to learn about the "cross hatch adhesion test" that would find this article informative and interesting.

Is my answer satifactory to you !

[astrid]

Thats fine , but why are you using 3 different user names?
just puzzled
Astrid

[MacS]

I'm trying to confuse you, but you got me this time.

BTW -I am not Macka, who is the second one?

I am MacS, which is short for Mac Simmons.

Any more questions?

[durwood]

Obviously things differ greatly in the USA

Here and in Europe the cross hatch test is always done as described by Macka.


Masking tape is designed to release easily after application, can't see using it would be much of a test. In paint testing labs here a better test is to use cellulose tape, as the idea is to get the coating to peel away from its previous coats Masking tape won't give a result as good if at all compared to a stronger tape.

I can't see any advantage cutting the tape the tape goes over the cross slashes and is meant to pull away the finish at the point where the cuts cross. thats the weakest point of adhesion. Cut the tape and you then have to pick at the different pieces to get them off where one full piece on top and a quick yank ( no pun intended) and it is still there or some part of the damaged arera has let go.

[Harry72]

That IWS website must be the slowest site on the net!

[MacS]

Whatever works for you, masking tape has been used here in professional testing labartories, and in coating manufacturers for decades.

Your right, many things are not the same in both countries. I think the article explains why the test is done, and tells how every one can check the adhesion on their own work.

Not, every one knows this, I am sure some readers may have learned something from the contents of my article.

[durwood]

If you google "cross hatch paint test" you will see several references to doing such a test, none of which is done by cutting the tape. The tape is placed over the cross hatch after the cutting.

This manufacturer of paint testing equipment suggests it be done within five minutes of cutting the paint.

http://www.paint-test-equipment.co.uk/Cross%20Hatch%20Cutter.htm


Normally the paint is allowed to dry as fresh paint may or may not be adhered properly but as you are producing a paint surface which will be used when it is dry it makes sense to see if it or others under it has adhered properly to the surface when they are dry.

[MacS]

Whats the big deal when the tape is applied, or the amount of time the tape is removed, if the adhesion is poor the coating will come off.

You do it your way, I'll do it my way, it works for me and many others, and has been for years, and that's what matters to me.