Build thread: 5.3:1 sport scale Super Deluxe #2 Skywriter XL Premium Pro Max - Limited Edition

[neil_w]

I am getting REALLY frustrated trying to polish my Lexan fins. I scratched them up pretty good early on, not realizing how soft polycarbonate is. While I could use them like that, I figured it ought to be possible to clean them up using some readily available product.

I started with 2000 grit sandpaper, followed by 3000 grit, followed by the full 3-step NOVUS plastic polishing system (multiple times), followed by multiple applications of Mother's plastic polish. My results:

That's a scratchy one on the left, "polished" one on the right. Certainly I adjusted the lighting to make it look as bad as possible. In real life it's not that terrible, but still definitely foggy.

Can't figure out what I'm doing wrong, or what I could do to fix it. Anyone have any suggestions? I'm spending many dollars on products to fix this and none of them are doing anything helpful for me. Was 3000 grit -> NOVUS polish too big of a jump? Do I nee to add a 5000 grit step in there or something? Should I try a headlight restoration kit?

At this rate this is going to hold up completion of the build. I need to do all the hard buffing work before the fins are installed.

 

[Speaknoevil]

I am getting REALLY frustrated trying to polish my Lexan fins. I scratched them up pretty good early on, not realizing how soft polycarbonate is. While I could use them like that, I figured it ought to be possible to clean them up using some readily available product.

I started with 2000 grit sandpaper, followed by 3000 grit, followed by the full 3-step NOVUS plastic polishing system (multiple times), followed by multiple applications of Mother's plastic polish. My results:
View attachment 408820
That's a scratchy one on the left, "polished" one on the right. Certainly I adjusted the lighting to make it look as bad as possible. In real life it's not that terrible, but still definitely foggy.

Can't figure out what I'm doing wrong, or what I could do to fix it. Anyone have any suggestions? I'm spending many dollars on products to fix this and none of them are doing anything helpful for me. Was 3000 grit -> NOVUS polish too big of a jump? Do I nee to add a 5000 grit step in there or something? Should I try a headlight restoration kit?

At this rate this is going to hold up completion of the build. I need to do all the hard buffing work before the fins are installed.

Hmm. I have installed them in 3 different designs. Tried to never touch them once removing the protective film (which was after they were epoxied and foamed in the fin can). They held up well over many flights. What was your motivation to sand/polish?

 

[neil_w]

Hmm. I have installed them in 3 different designs. Tried to never touch them once removing the protective film (which was after they were epoxied and foamed in the fin can). They held up well over many flights. What was your motivation to sand/polish?

All the scratches I applied during initial handling.

The reason I removed the protective plastic was because (a) I needed to do work on the edges, and eventually flame-polish them, and (b) I had no idea they would scratch so easily.

 

[Speaknoevil]

All the scratches I applied during initial handling.

The reason I removed the protective plastic was because (a) I needed to do work on the edges, and eventually flame-polish them, and (b) I had no idea they would scratch so easily.

I really don't remember them being overly easy to scratch. It is possible that I applied Future to the fins right after removing the film though. After though, they saw many flights. Here is a picture right before I sold one of them. Significant scratches are not evident, what you see is mostly halogen light reflections off the undulations in the surface.

 

[jqavins]

I've got this set, or one very similar. It goes up to 12,000. I've used it successfully to restore the shine to a polystyrene nose cone. I used every step in sequence and had to go nearly all the way to the top. Also, don't be in a hurry to step up; make sure, for instance, that all of the 3200 grit scratches are removed by the 3600 pad before going to the 4000 pad, because taking the 3200 scratches out with the 4000 pad will take a lot longer. Of course, with these really, really fine pads it can be hard to tell, and I did end up having to go backward once or twice.

 

[neil_w]

Yeah, I'm starting to think that 3000 is way too coarse to jump straight to the polish. *sigh*

It occurred to me after my previous post that I meant to try some Future on the cloudy fin and see what happens. Well, it can eventually work OK. I ended up applying a bad coat of Future, then polishing *it*, and then another coat of Future that looks somewhat better. It's by no means perfect (the Future didn't really level as well as I would like, maybe I'll try diluting it a bit with some Simple Green) but it's *clear*.

 

[ebruce1361]

Please excuse my lack of knowledge on this, but what is this "Future" you are referring to? I am familiar with the future Doc Brown and Marty have to keep going back to, but that's about it. Is this some kind of polishing compound?

 

[Greg Furtman]

Please excuse my lack of knowledge on this, but what is this "Future" you are referring to? I am familiar with the future Doc Brown and Marty have to keep going back to, but that's about it. Is this some kind of polishing compound?

Future is a Pledge Acrylic Floor Gloss. Many of us use it as a final gloss clear coat.

 

[ebruce1361]

Ah! I have heard of using Pledge floor polish (still have yet to try it myself), but I hadn't heard of it being referred to as "future" before. Much appreciated, carry on!

 

[kuririn]

Future was the name of the product in the primitive era.
Like CWF was called something else in the cave man days.
And conversations were called private messages.
Lots of us primitives lurking around here.

 

[neil_w]

For many many years it was called Future. I remember the commercials on TV at least dating back to the 70's.

In recent years it has gone through a mind-boggling sequence of name changes. Because it spent a long time as "Future" and then only a short time with various other names, Future is the one that folks normally use. Here is the definitive reference: https://www.swannysmodels.com/TheCompleteFuture.html.

 

[jqavins]

Ook gronk og!

 

[Greg Furtman]

Future was the name of the product in the primitive era.
Like CWF was called something else in the cave man days.
And conversations were called private messages.
Lots of us primitives lurking around here.

I resemble that remark!

 

[kuririn]

I resemble that remark!

Woop woop woop woop
Nyuk nyuk nyuk

 

[mbeels]

Just curious Neil, how does the clarity through the fin change if you put a piece of scotch tape on each side? Does it get better, worse, or stay the same?

 

[neil_w]

Clearer, although that one fin is already pretty clear now with Future slathered all over it.

 

[kuririn]

I think there was a liquid that opticians used to cover up scratches on glass lenses.
I'll see if I can find it.

 

[jqavins]

Do you actually mean on glass lenses, or on the plastic lenses in glasses? It matters because the latter is likely to give better results. (Plastic glasses lenses are often polycarbonate, so such a substance probably has a close match to that in its index of refraction, but might be considerably off for glass, and the closer the match the better here.)

 

[kuririn]

Correction, plastic lenses in glasses.
I found these substances in various articles found in a search that are suggested for removing scratches on plastic lenses.
1. Toothpaste. Low abrasive type.
2. Baking soda. Make a paste with water.
3. Metal polish. After polishing clean thoroughly with alcohol.
4. Car cleaning wax. Fills and smooths scratches. May only be temporary, might need to reapply.
(I'm wondering if car cleaning compound, like white compound, is too abrasive?)
5. If the previous fail, "glass" etching cream with hydrofluoric acid may work. Use only on plastic, the acid will remove the outer coating of the plastic and buff away the scratch.

In all cases use a non abrasive cloth, like micro fiber.
PS How to apply wiki: https://www.wikihow.com/Fix-Scratched-Glasses

 

[Greg Furtman]

I've used a 3M headlight restoring kit on both of my cars & it worked really well. Headlights are plastic these days. I wonder if it would help.

https://www.amazon.com/3M-39014-Len...583968034&sprefix=3M+headlight,aps,218&sr=8-7

 

[BABAR]

Future was the name of the product in the primitive era.
Like CWF was called something else in the cave man days.
And conversations were called private messages.
Lots of us primitives lurking around here.

Sooooo, technically in the remote past it was referred to as “Future”

Where is Michael J Fox when you need him?

 

[BABAR]

I've used a 3M headlight restoring kit on both of my cars & it worked really well. Headlights are plastic these days. I wonder if it would help.

https://www.amazon.com/3M-39014-Lens-Renewal-Kit/dp/B002UJ13QO/ref=sr_1_7?crid=2A01W6PY9Z7WD&keywords=3m+headlight+restoration+kit&qid=1583968034&sprefix=3M+headlight,aps,218&sr=8-7

At $16, price isn’t bad, and they have free returns if it doesn’t work.

 

[Speaknoevil]

First it was fire, then Future, then the wheel...

 

[kuririn]

First it was fire, then Future, then the wheel...

Gotta keep those cave floors nice and glossy.
Need to protect the dirt from the.....Hey wait.

 

[jqavins]

Well it may only be about the appearance but, hey, take some pride in your cave!

 

[BABAR]

For those of us handicapped by having only one "X" chromosome, the "cave" is our only refuge at home!

 

[Nytrunner]

In recent years it has gone through a mind-boggling sequence of name changes.

Quick! What's the difference between Titebond Molding and Trim, No-run No-Drip, and Quick and Thick!?

 

[neil_w]

Quick! What's the difference between Titebond Molding and Trim, No-run No-Drip, and Quick and Thick!?

The color of the bottle.

That product wins the silver, pretty sure Future has gone through more name changes than that.

In the meantime, my adventure with trying to Future these fins has been disastrous. Although I had "decent" results with the first fin, on the next one the Future would not adhere to the fin surface at all, rather it would bead up which is definitely not what you want:

The Future can be removed, so this isn't permanent, but man oh man it's driving me bonkers. I've kind of lost track of all the things I've tried in all different combinations. Nothing is working consistently.

 

[BABAR]

The color of the bottle.

That product wins the silver, pretty sure Future has gone through more name changes than that.

In the meantime, my adventure with trying to Future these fins has been disastrous. Although I had "decent" results with the first fin, on the next one the Future would not adhere to the fin surface at all, rather it would bead up which is definitely not what you want:
View attachment 408960
The Future can be removed, so this isn't permanent, but man oh man it's driving me bonkers. I've kind of lost track of all the things I've tried in all different combinations. Nothing is working consistently.

Maybe you got a bad batch of lexan?

 

[Speaknoevil]

The Future can be removed, so this isn't permanent, but man oh man it's driving me bonkers. I've kind of lost track of all the things I've tried in all different combinations. Nothing is working consistently.

Actually it cannot in this case. I have to apologize if I sent you down this course. I now remember that I considered applying Future to the fins on my "Color the Sun" Crayon rocket, but I did not. This is because of the cleaning issue. You cannot apply ammonia (dissolving agent for Future) to Lexan as it, like Future, is an acrylic and it will be weakened. See: https://www.acplasticsinc.com/informationcenter/r/polycarbonate-sheets-cleaning-care. At this point, it may be better to start all over.