I have had a set of micromesh pads i bought from Giovanni ages ago and still have not had the guts to use them. You see i can't get my head round the fact that you have a plastic, celluloid, casein pen with scratching and to smooth them out you use abrasive pads Please someone educate me.

I'll give it a go....

Essentially, you have minor scratches in your pen, right?

So you take a lower grit abrasive pad to evenly level the rest of the material around the scratch. This gets rid of the scratch.

But then you have an issue, because the abrasive pad left it's own very light scratches in the pen, right?

Well, you then go to the next higher grit to get rid of the scratches that the last grit created.

And so on, and so on, until you get to 12,000 micromesh. The scratches left by the 12,000 micromesh are basically invisible.

So you are hiding scratches that are left by previous grits of abrasive by increasing the grit each time.

Just never skip a grit. And always wet-sand with micromesh. Use water or mineral spirits as a lubricant.

And then from there, I like to use a plastics polish, and a light wax.

You're 90% there.

First - don't use mineral oil on plastic. Maybe on glass, but in plastic, water is the better option.

With any abrasive, you're removing material. The coarser abrasives remove material faster, but leave scratches behind. As you move up through the finer grades of abrasive, the material is removd more slowly. Each grade still leaves scratches behind, but they are much finer, and the surface smoother, so you don't see the scratches. Micromesh 12,000 is one of the finest abrasives. Even plastics polish contain very fine abrasives, but they're fine enough that they leave a very smooth finish.

The idea behind using water with wet-or-dry sandpaper (like 1200 or 2000 grit) and Micromesh is two fold. 1] To provide a lubricant so that the material cuts better. 2] It allows the removed material to float away, and keeps the abrasive from clogging with the material being polished.

//First - don't use mineral oil on plastic.//

Well, in my post I said mineral spirits, not mineral oil. Perhaps you misread.

I like mineral spirits because it acts as a solvent to grease and oils.

I won't use it every time that I'm polishing a pen, but with most I do.

I got used to using it because it's my preference for wet-sanding on the lathe. The reason is that water will rust my lathe, wheras mineral spirits will not.

So I'm not sure if you misunderstood, Ron. What are your thoughts on mineral spirits?

Right thanks now i get the science of it. How will water affect my neat little micromesh pads?? and should it be a constant flow of water or just wet??

Constant flow? no, just a recipient with water in wich you might rinse every now and then your pad. Water will keep them pads neat and clean. Also, the third and so far unmentioned effect of using water is to provide some sort of surface lube, wich, even permitting the abrasives to cut cleaner and "faster" (not) prevents them from dry cutting to harsh on the plastic

As a rule of the thumb, I NEVER use the 1500, 1800, etc when a pen only has MINOR scratches. (Say, your everyday writer modern Pelikan, wich are prone to get superficial scratches) I go on from 4000 there.

If you have a lathe, you can build yourself some wooden mandrel to hold the pen there and use the pad while rotating at 500 rpm or so... it will allow you to use a more random attack angle (less detectable to the eye, even under magnification) I use this way, start with one grade, then reverse the lathe and use the next grade n opposite rotation, and such. If you don't have a lathe, then cross cutting is a must.

I did misunderstand - it's been a long day.

Mineral spirits - paint thinner right? I still feel uncomfortable using that on a pen, though I have used naptha to remove adhesives for years. I still wash the pen off after I'm done though.

I also understand the issue of wet sanding on a lathe. If it's a mini-lathe there are accordian like covers that attach to the lathe and cross feed that protect the bed - or you can do what I do and lay a piece of rubber or paper towel over the bed to protect it. Assuming I'm not so engrosed in the project that I forget.

//Mineral spirits - paint thinner right? I still feel uncomfortable using that on a pen, though I have used naptha to remove adhesives for years. I still wash the pen off after I'm done though.//

Yes, I do wash it off afterwards.

Mineral spirits is one of the mildest of solvents and is very similar to naptha. I would never use lacquer thinner, or acetone.

And even though denatured alcohol is also very mild, I would never use it on a pen, as it could melt any shellac seals.

And I really have no problem with using water...I'm not trying to push mineral spirits on anyone.

If I am doing a thorough polishing of the entire pen, then I think water is fine, because you are going to remove any oils or grease with the abrasive action.

However, if you are working on one specific area of a pen, I prefer the mineral spirits because you will be thoroughly cleaning off the grease and oils, and then you can later wipe down the other surfaces of the pen to keep the entire surface consistent.

Thanks for your feedback.

There are really to aspects to sanding, and polishing. Either you start with base material, and remove it in sequencial steps in order to obtain the flatest possible surface, or you add material to the base to fill in the lines and grooves, and then work the coating down to the smoothest, finest surface possible. It is a real possibilty to eleminate the "seen" scratches by applying a top coat, and then work on it leaving the original in tact or with only minute reduction of the base. Much like giving a peice of Oak a mirror like shine. It is not easy, but it can be done.

Not only that, but alcohol will disolve celluloid. A bit on a rag will cloud the finish, but a dousing of alcohol on celluloid can make a mess of a celluloid pen very quickly indeed.

dont know how it would be on celluloid but i would try toothpaste rubbed on with soft kitchen paper. I removed a scratch on a watch glass using different grades of sand paper and emery then did final polishing with toothpaste. Fantastic results.
Armchop