Finish for Acrylic/plastic

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Smitty37

Passed Away Mar 29, 2018
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What do you use to finish plastics....I take them 2 12000 micromesh and they are pretty shiney but don't have the "glass" look (this is good - I am not overly fond of that look). I am considering just using turtle wax as though it was a car....

Any thoughts ---- please don't suggest CA I wouldn't touch that with a stick.
 
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Smitty37 said:
What do you use to finish plastics....I take them 2 12000 micromesh and they are pretty shiney but don't have the "glass" look (this is good - I am not overly fond of that look). I am considering just using turtle wax as though it was a car....

Any thoughts ---- please don't suggest CA I wouldn't touch that with a stick.
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I used to finish with plastic polish after the 12000 MM, but I've started buffing with tripoli and then white diamond after the 4th MM grit, whatever that is. 3200 I think. I think the micro scratches have decreased, and it is a lot faster and easier of a process.
 
Smitty37 said:
What do you use to finish plastics....I take them 2 12000 micromesh and they are pretty shiney but don't have the "glass" look (this is good - I am not overly fond of that look). I am considering just using turtle wax as though it was a car....

Any thoughts ---- please don't suggest CA I wouldn't touch that with a stick.
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Well there are many options but the fast easy choice would be liquid polishes. Products like novus and plastx use the same ingredient but in these 2 listings novus #3 has 3 times the density of the abrasive powder which means it works much faster. There are a good number of other liquid products that you can use to get the same effect. Also with liquid there is no need for micromesh.
 
PARDON ME FOR MAKING A MISTAKE!!!

And Ed, i wont comment on your reply, you know where to put it, trying to be nice when i don't want too:biggrin: But your more than welcome to give your opinion on Smitty's question rather than bash others for thiers, now thats an idea.
 
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longbeard said:
PARDON ME FOR MAKING A MISTAKE!!!

And Ed, i wont comment on your reply, trying to be nice when i don't want too.
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I meant nothing personal about it and you are not the only one either. I just saw this listing. Doubling the work has been a big pet peeve of mine especially when you see the volume of posts with those having major problems doing CA finishes and a good hefty majority of them are over sanding.

Believe it or not but I am trying to encourage everyone to work smarter and not harder.

michael j flett said:
After mm i use T cut for cars its basically Brasso then turtle wax polish seems to work just fine worth a try and not expensive.
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I am not sure where I should start on this one.

Brasso ingredients: ethanol, oxalic acid 0-3%, isopropyl alcohol 99% 3-5%, ammonium hydroxide 5-10%, limestone/silica powder 15-20%, pumice.

-- did you see the ammonium hydroxide 5-10% part? Way better products to use.
 
I've read about going backwards to buffing with tripoli after polishing with mm to 12,000. But it seems that somewhere I read that it's not all in the grit but changing the direction of the scratch pattern.

Any comments
 
I go through all the MM pads and then use Hut plastic polish. I may be doing more than necessary, but I believe it looks better after the plastic polish so I keep doing it.

I have to get my buffing technique down though. I tried a couple of times with Triploli and white diamond and just was not happy with the results, user error I am sure. My opinion is that Larry is correct that changing from the on lathe radial pattern to buffings logitudinal pattern does offer benefits.
 
sanding on the lathe yield radial patterns and the only way to remove those is sanding 90 degree's from said marks. this holds true with everything not just on the lathe. Classic sanding approaches tells you grit A is up/down, grit B is left/right, grit C is up/down, etc.. that way the smaller grit removes the larger grit and there is less chance of having gouges in the surface. However at the end with the polishing materials movement will be 90 degree's from the last sanding direction for optimal results and yield the fastest time. The kicker with this statement is "what is the last grit used for sanding" That can be very tricky as it depends on the material and where you are planning on ending. Some materials will sand up to 800 grit while others 400 grit. What you are looking for is what grit does shaping stop at, that is the final grit. If you are finishing on the lathe then you want that grit to be left to right.

If you sand in the same direction for all grits then you will 'banding' or ripples all over the blank. Another aspect that many finishers may not be aware of is patterns in the sanding media. That's right, patterns of how the abrasive material is added to the sheet. This is more noticeable with abranet than with sandpaper but even with micromesh those patterns are still there.

For those who are using micromesh and going to a liquid polish I would urge every one of you to experiment with eliminating grit sizes from micromesh and see what the results are. My suspicions are the micromesh finish is not complete when you switch to liquid and the liquid is undoing everything the micromesh started but did not finish. Liquid polish is also well known to be a faster process and this is likely why they are being overlapped like this.

Buffing is no different than other methods but depending on material sometimes it's the best choice possible. Generally you want to use one compound on 2 or 3 types of wheels before going to a finer compound. Hard and soft wheels tends to work the best for this. Same rules apply with the grain direction I mentioned above.
 
This is what I am talking about on sanding direction.

pk_use01_e.gif

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This is the ancient art of Togi, sword polishing.

The base building and shaping is in a diagonal direction.
Then up/down is applied to remove the coarse, note there are multiples this is one hard and one soft (as I mentioned with the buffer in last post)

Then left/right is applied, this to is hard/soft. the final 'sanding' is the up/down stones and all polishing after that is left/right due to speed on how it is polished.
 
Didn't somebody post a really good breakdown of the finishes with their relative grit values It seems I read that recently? It compared mm to novus etc..
 
After a previous post where I asked about Novus 3 and some responses from Ed, I've really decreased the amount of steps needed in my finishing process. YMMV but this is what I've cut down to so far. I don't claim this to be the right way, just my way that works for me so far.

Turn, 400 dry, 600 dry, 1500 wet, 2400 wet (both of these are 2 sides of a single pad from the Barry Gross plastic finishing kit) and then right to Novus 3 and Novus 2. I will then hit a buffing wheel simply because I don't have any Novus 1 on hand to get the final polish step.

Once I find a quality 800 grit, I'm likely going to replace the 1500/2400 steps with the 800 and then move right to Novus. So 400/600/800/Novus3/Novus2/Buff (or Novus1)

I find that sanding is all about the speed, the pressure you apply and the material in question. If you are leaving deep grooves with 400 or 600, you are probably applying too much pressure or using crappy sandpaper.

You have to find the happy balance for your process which is why there are so many wildly varying processes out there.
 
And actually as I'm looking at a chart now, going to 1500 MM is actually a step backwards. I could probably omit that completely and not miss it. The 800 is right between 1500 and 2400 so I'm fairly confident that it will be a good direct replacement for both MM grits.
 
I mm to 12000 then apply Huts' ultra gloss...1st coat with a little friction to set the wax and then apply another coat and softly buff at high speed. Then depending on the pen, I'll apply 1-2 coats of ren wax for protection during assembly. I'm not saying this is the only way but I love the results.:wink:
 
Wet sand 320, 400, and 600. Then to the brown and white wheels on the Beall system. For a really high gloss, I often run the Beall-buffed blanks back onto the lathe and buff with the fine Novus.

In fact, I took off the third wheel to allow more working room between the 2. I will add it back in when I get into more bowls and such.
 
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I have only done a few acrylics but for those I did 400-600-800-1000.. MM 3200-12,000 then a buff with white rouge and on loose cotton wheel.
 
I am new to this but I am currently using the Beal system. Wasn't really happy with the results so I eliminated the third step. It seemed to make the shine cloudy is why I stopped using it. I liked the shella wax but was looking for something different as well. Going to try CA next so I'll probably end up trying everything eventully. So all you know some of us Noobs are reading you posts.
 
GRMiller said:
I am new to this but I am currently using the Beal system. Wasn't really happy with the results so I eliminated the third step. It seemed to make the shine cloudy is why I stopped using it. I liked the shella wax but was looking for something different as well. Going to try CA next so I'll probably end up trying everything eventully. So all you know some of us Noobs are reading you posts.
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I've never heard of using shellawax on plastic.

Also, ca would be like putting plastic over plastic.

I you don't like the buffing wheels, just get some novus or other good plastic polish.
 
Dan Masshardt said:
GRMiller said:
I am new to this but I am currently using the Beal system. Wasn't really happy with the results so I eliminated the third step. It seemed to make the shine cloudy is why I stopped using it. I liked the shella wax but was looking for something different as well. Going to try CA next so I'll probably end up trying everything eventully. So all you know some of us Noobs are reading you posts.
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I've never heard of using shellawax on plastic.

Also, ca would be like putting plastic over plastic.

I you don't like the buffing wheels, just get some novus or other good plastic polish.
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It works ok on plastic, probably because of the wax - it doesn't add a lot of shine though.
 
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