HOW TO: Flame polishing acrylic

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Flame polishing acrylic with propane…. DO NOT weld a flame polished edge… this is only for exposed acrylic that is not to be welded


The king of DIY


What do you think?


Written by The king of DIY

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  1. Propane is not recommended for polishing acrylic edges – it is not hot enough. A better choice is MAPP GAS, which reaches a higher temperature and leaves a smoother finish.

  2. Hey Joey I'm new to the reef hobby and I own a 29g Biocube. I'm now designing a Frag Grow Out Tank from Acrylic. So here's my question. Can you Flame Polish after Assembly (WELDED)? I have researched for a few months now off and on but I'm more confused now than ever 😉 Ok, I do understand you CANNOT weld polished edges but…After assembling is what I need to know more about. Check out this vid at 2:38 it appears as if he polished afterwards. Any info is greatly appreciated. Thank You Kindly for your time. Take Care.          Sincerely, Kristi

  3. I have an IMPORTANT question. I've attempted building an acrylic refugium out of <6mm sheet stock. I have made initial cuts on a table saw and have unsuccessfully managed to get a good mating surface for joining. Flame polishing gives a "finished" appearance but still does not insure a flat mating surface. Once my two sides are welded together, leaks prevail. Do you have, other than buying an expensive planer, a method of resolving this? Many thanks! Don

  4. Hi Joey- thanks for the video on bending acrylic! It saved me from cutting 4 pieces. Instead I cut 2 & bent the corners where I needed them. Makes for a much neater work & a time saver. Working on a different project than an aquarium-but the technic works the same. Great video! God bless.

  5. Great video!
    How do you prep the edge before you polish it? I sand my edges on some pieces with a belt sander, do you recommend working to a finer paper before polishing?

  6. Joey no doubt you heard this before so apolpgies in advance, I looked but couldn't find this obvious question. Do you think it would be easier to flame polish the edges before assembly? only ask because thinking if I cock it up I can just replace the acrylic, cheers for any help mate (subbed and on the forum bro)

  7. well don't watch the video if it annoys you. his videos have helped tons of grateful people eager to learn. his intent is not to be lectured on his videos. joey i appreciate all your videos dude. keep doing what you do. your the only one putting out quality informative videos that actually help and allow us to understand aquarium builds.

  8. Still yet, I'm a Certified Structural Welder & am quite familier with plastic burns. They can be worse than steel burns because the melted plastic won't come off your skin like steel will & the heat will burrough deep.
    This is why LEATHER WELDING GLOVES for this work is ideal. You can buy good gloves as cheep as $7. Make sure to get WELDING GLOVES & not just your common leather gloves. They are padded inside & much more heat resistant.

  9. In uarujoey's series on building an acrylic aquarium he flame polishes the edges after he has welded the tank together. There are 6 parts to the series, I'm pretty sure it's in part 5 or 6.

  10. Hey man so i build an acrylic cube aquarium just as my first attempt with acrylic and now i want to flame polish my edges but i can find anywhere or nor do you say if you can flame polish edges that have been welded together. I want to do this so that i get a clearer edge for viewing. Also i dripped the weld on 3 everywhere so i wanted to flame polish it off but i wanted to make sure it is okay to do on the corners before i go and do this.
    Thanks for the awesome videos and all the great info!

  11. the maximum adiabatic flame temperature of propane is about 2000 deg C or 3600 deg F. On the propane torch flame, you'll notice there's a brighter inner blue cone and a fainter outer blue halo. The tip of the inner blue cone is the hottest part of the flame. That's what uarujoey was putting on the edge of the acrylic.

  12. @ogmonkey27

    typical sheet size is 8ft x 4 ft, price depends on thinkness… if you want a large tank you could buy a sheet on 10-12mm and cut it 2ft of the end to leave you with 6×4 sheet then cut it into thirds lenghways then you will have 3 @ 6×1.3ish. make those your base and sides. cut the 2x4ft piece that you inicially cut off and use it for the ends. a 8×4 @ 10mm is roughly AU $300. + cutting and a bottle of weldon 4. you probably looking at 400. not a bad price for a 6ft tank

  13. @SupremeJudge

    Sanding dulls it…It's best to flame it, and it REALLY helps to polish it afterwards with a cloth, or better yet a buffer wheel to get it as clear as the whole sheet.



HOW TO: Weld Acrylic

HOW IT WORKS: Large aquarium