Flame finish?

[SDB777]

I was cruising the YouTube site the other day and came across a duck call maker using a blow torch to 'finish' the barrel on his duck call...he stated it was 'acrylic'(which type I do not know).

He sanded through the micro mesh grits and then pulled out one of those small butane torches with an adapter on it and went to town with it....just quick passes and the difference was pretty amazing....



So the question to all here...Has anyone tried this?



Scott (sure tired of the rain here) B

 

[firewhatfire]

It didnt work well for PR blanks. All I did was ruin a good pen blank.

 

[SDB777]

It didnt work well for PR blanks. All I did was ruin a good pen blank.

Was it the thickness of the material being 'flamed'?
What happened? Did it involve a fire extinguisher??





Scott (I'll need to find the vid now) B

 

[firewhatfire]

no fire extinguisher needed in my shop yet, I am told its a wonder. I was trying a silmar 41 blank I poured to see how it worked. All I did was misshape the piece and scorch it a little. Mostly it discolored it(happened almost immediately) It was a bottle stopper I think.( I have done so many things I shouldn't have since then thatI cant really remember)

 

[skiprat]

I once saw a shopfitter put a flame to an edge of about 6mm thick clear sheet he just cut. It did leave a couple of the cut lines, but it was really smooth and shiny.

 

[Jeff-in-Indiana]

According to TAPP Plastics, this works on Plexiglass, but not polycarbonate .. mapp gas only, propane will not be hot enough (they say)
How to Polish and Shape Plastic Edges - YouTube

 

[PTsideshow]

It is done on the cut edges of sheet acrylic and then some brands work better then others. Proprietary formulations probably have something to do with it some of the resins used have higher volatiles in them. It is called flame polishing. Mostly on cut edges were the sanding and polishing is a pain. Did it with a lot of of display bases/prop that were fabricated.
Think the single pen holders some use for display and photos on here, if they were cut out of sheet stock.
Use to use a regular propane torch, with or with out a flame spreader. the distance of the flame from the plastic, the speed you move the torch and the time you spend heating up.(temp of the acrylic) all plays a part.

Practice, practice, practice and skill is required. best to do scrap pieces first. I ruined a large display base in the last 3", it was made out of ½"x4'x4' sheet. Had to use another sheet. was lucky that most of the first half could be reused!

Flame polishing uses a hot flame to flow a plastic surface. Operator skill is critical with this method. When done properly, flame plastic polishing produces the clearest finish, especially when polishing acrylic. Flat external surfaces are the most applicable configuration for this method.

Flame polishing edges This wood web is about professional wood workers a lot of the equipment and projects are big. But the section on adhesives and glue ups has some great info. Read thru the comments and you will get a pretty good idea about flame polishing.
:clown:

 

[PTsideshow]

According to TAPP Plastics, this works on Plexiglass, but not polycarbonate .. mapp gas only, propane will not be hot enough (they say)

It does take longer to achieve the same results with propane, any flame source will work its just a matter of keeping the flame moving to heat the acrylic with out melting it to much

A heat gun with an extremely thin slot type opening heat spreader, would work but that is a whole new learning curve skill set, They are great for fabricating sheet goods.
:clown:

 

[SDB777]

Finally had a moment to go look for this video on Ytube.

How to flame polish an acrylic duck call barrel - YouTube



I don't think this is a plexi sheet? Although I've seen those being done too.



Scott (changing colors = no good) B

 

[Brooks803]

Scott, I tried this with a PR blank while I was at my friend Han's house about a week ago. We turned a small piece between centers and sanded up to 400 I think. After hitting it with a flame (propane torch) much like the video we had some decent results. I think there is a learning curve, but I also think you need to sand up into the micromesh pads to get a super smooth finish with a flame. By then I figured what's the point? Stop and get out a torch to do what can be done with a couple more MM pads? Still fun though! Just be CAREFUL of shavings and anything else flamable around the lathe!!!! Most of us don't work in such a sterile setting as the guy in the video.

 

[studioso]

I ASSUME THIS DOES WONDERS WITH CELLULOID PENS...

 

[wolftat]

There is a special torch used in flame polishing (actually burns with water) and it works great with plexiglass but I wouldn't bother with it on most other acrylics. It is used mostly in the sign and award industry.

 

[gwilki]

I've done it with plexitone finished on a couple of pens. Many moons ago, I made acrylic aquarium hoods and that's when I first flamed edges. I thought that I would try it on pens. While it worked, I could get very similar results with fine sanding and good polishes.

 

[BKelley]

In the course of my duties while working for the local school system, I had to fabricate sneeze guards for lunch room serving lines. I used clear aryclic, sanded the edges and then used an acetylene torch to make the edges clear and glossy. Had to use extreme caution to keep from burning the aryclic or bringing bubbles up.

Ben