TOTW 02-01-05 Cutting plexiglass and glue

[scubadude]

I would recommend against using a circular saw as it could bounce or jiggle and crack/chip the stock material

Once you have your pieces cut but them together and lossely apply a clamp. using a syringe flow the cement along the seam of the to pieces to be joined. Always flowing clue horizontaly and not vertically.
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Perfect advice.. I have built a couple sumps/refugiums and skimmers using this same type of advice. Weldon 16 is actually MUCH easier to use then the 4 or 8 (lower numbers = less viscosity). The 16 is about right for most people as its a consistancy similar to epoxy, it doesn't just run all over the place. You will although have to be aware that drips/spill if not cleaned up instantly will result in 'burns' in the acrylic.

There are two opinions here both of which have great merit. I have used weldon 3-16 on varying projects H20 Aquatic solution does this for a living so I understand his approach as being more finely detailed. I believe your cuts will sole relate to the type of glue you can use. The pin-method has been used widely for welding acrylic/plexi together. Which is utilized by sticking straight pins inbetween your welds and applying the weldon between the surface joining contacs and removing the pins before the weld connects.

Samper what type of cutting tools do you have? I use a circular saw with carbide tip blade and very little kerf (if any) the more teeth the better it will cut but the more you will want your blade to be kept clean, and possibly using a flushable coolant such as water cleaning/cooling your cut. I dont like the idea of having to do a cut in steps allowing for cooldown of the blade as this will make a cleaner cut but will give higher odds for uneven flush edges where you stopped the process of the cut.


H20Aquatic, (Or anyone for that matter)

Do you have any pics of Jigs/templates/guides that you have made? That would be a great tangible asset to this thread.

Pavesi,
The problem I have w/weldon 16 is its too thick, and not as neat in seals as the weldon3 or 4, I also have played around mixing different ones to make a more ideal viscosity for the purpose. The times that I have used 16 is when my cuts didnt come out like I wanted them too I have seen a few ppl use 16 with great clean joints but its usually someone who has been working with acrylic for a while. Of course this is all ordained by how finicky the creator of the project is.

[pavesi]

Rocky,
Thanks for the input! I agree that 16 for people that have/get clean edges is not as 'nice' re filling. My personal preference of 16 is for those people without table saws, jigs, and have/has not been working with acrylic for some time. Without a doubt if the project is for customer use/sale, or for items that will be in display, then you will want to use 3/4 to get the most professional looking peice possible. If the item is just a personal skimmer in a sump, then yes, it will come down to the individual to decide what is best for them.