Acrylic "ink windows"

[Texatdurango]

Just sharing some thoughts.....

In another thread Jeremy showed us his beautiful pen with an ink window. He was asked how it was done and mentioned that he did his similar to the way I do mine so rather than derail his thread I thought I would start another thread to show this photo.

There are two things I hope you take away from this post, one of course is to see how you can make an ink window using clear acrylic tube and second is to NEVER clean the inside of the tube with denatured alcohol.

The top item is a clear demo body I made several years ago that cracked into a million pieces when I ran a swab soaked in alcohol inside. I just swabbed it again a few minutes ago and the cracks got worse so it obviously doesn't matter when you do it.

The bottom item is an ink window I made for a bulb filler pen. After taking 30 minutes to cut and thread the piece, I applied shellac to glue the bulb on and wanted to make sure nothing got inside the tube so I grabbed a swab and soaked it in alcohol to clean the inside when... BAM, it cracked in three places.

I'm no chemist so don't know why these cracked, they weren't hot, and as I stated, I just rubbed the inside of the top piece minutes ago, easily three years after the first cracks and it cracked more so I don't know why, I just know it cracks.

I think I had a total of three or four pieces crack like this so I just quit using alcohol all together to clean the barrels. Perhaps it's the particular brand of acrylic I use, perhaps it's the brand or strength of alcohol or that I'm just left handed and things like this happen to me now and then.

Back to the ink window briefly, I've made a few windows from rod stock where I drill out the inside, sand and polish until clear but that's more work than I care to dedicate to each pen so I usually use acrylic thick wall tubing where the hole is already drilled and polished.

I use fine threads such as .5mm and glue my pieces together. Even using glue on the threads, I still want the fine pitch thread so as never to leak a drop of ink. Once the window is glued into the body, either at the top, bottom or middle, I remount the blank in a collet chuck and sand everything smooth to where you can't feel the seams, and polish until the window is crystal clear.

 

[oneptbuk]

I work in an industry that uses clean hoods for compounding sterile products (drugs in this case) and it's been well established to not use alcohol (ethyl) on any of the plexiglass areas of the hoods. It sounds like it may be the same chemical property causing issue in your case as well. I don't know the chemistry behind it, and different properties between 'plexi-' glass and the acrylic you use, but it sounds like one of those 'don't know why, but don't do it' scenarios.....

 

[dow]

Thanks for the warning George. It's timely advice.

Dow

 

[bitshird]

Thanks for the warning George, I wonder what other cleaning agent could safely be used? Glass cleaner would be out since it contains Alcohol, perhaps a diluted solution of mean green, or some similar home cleaner?

 

[Timebandit]

Thanks for the warning George, I wonder what other cleaning agent could safely be used? Glass cleaner would be out since it contains Alcohol, perhaps a diluted solution of mean green, or some similar home cleaner?

Whats wrong with a little soap and water, and an ultrasonic cleaner. Thats what i use. Works fine. I dont see the need for anything special.

 

[glycerine]

George, the cracking thing is interesting, because I am making a pen for a lady who wanted the pen to be the color of her husband's car. I drilled out some clear acrylic rod to reverse paint. Once I applied the paint to the inside (got a bottle of touch-up automotive paint the exact color of the car), I saw tiny cracks throughout the acrylic. I thought maybe it was from the drilling process and I just could see them until I applied the paint, but now I'm thinking it's the same reason that alcohol cracks it, whatever reason that may be...
Ok, moving on to the topic at hand, thanks for the ink window tips! Do you use shellac to glue both sides, or just the bulb itself? I guess with shellac, you could get it apart later for repairs? I used two part 5-min epoxy on mine...

 

[Texatdurango]

Thanks for the warning George, I wonder what other cleaning agent could safely be used? Glass cleaner would be out since it contains Alcohol, perhaps a diluted solution of mean green, or some similar home cleaner?

Whats wrong with a little soap and water, and an ultrasonic cleaner. Thats what i use. Works fine. I don't see the need for anything special.

Nothing wrong at all with soapy water, that and my ultrasonic cleaner from harbor freight have been working fine for years now. I guess I should have mentioned the alternative that I switched to instead of the alcohol.

Great minds think alike!

 

[Texatdurango]

.........Ok, moving on to the topic at hand, thanks for the ink window tips! Do you use shellac to glue both sides, or just the bulb itself? I guess with shellac, you could get it apart later for repairs? I used two part 5-min epoxy on mine...

I use shellac just for the rubber bulb, I have used both epoxy and CA with equal success to glue the acrylic to acrylic joints and use just epoxy to join the clear window to ebonite or wood bodies.

They used to use shellac to glue just about everything together, even sections glued into pen bodies so I assume it would work just fine but I don't plan on anyone taking apart the pen where the window meets the body so I glue it in permanently.