What's the best way to cut acrylic?

[kdc527]

I am going to be building some overflow boxes because one of my glass ones cracked. I have a prototype built but I had a contractor cut the acrylic for me. Now I can't get ahold of the contractor to find out what he used to cut the cellcast with or what he used to cut the teeth into it with. Any help would be appreciated. thanks.

[uncleof6]

Table saw and a router (on a table also)

Jim

[kdc527]

What type of blades and bits a large router or laminate router. I am afraid that the cellcast will melt and i won't have a good edge to glue to. While I have the thread open i would really like to get some extra space in my tank how difficult is it to make an external overflow box. The distance I need to drain my water to my sump is pretty far so an external box seems like a good option to me.

[project]

a fine tooth saw blade works well and it helps to use a 0 gap insert on the table of the saw to help stop chipping on the back side. Use a stop block on the miter fence and cut your slots there. Hope this helps

[uncleof6]

84T carbide tipped plywood/laminate blade, however don't go out and spend $100 on a saw blade either. A spiral upcut bit for the router to finish the edges. A table mounted router with fence would be the best.

Actually the best way is to have an acrylic shop do it for you.

Overflow boxes are simple, but if building out of acrylic, I will let the acrylic folks deal with that.

Jim

[kdc527]

uncleof6 how would you suggest to build an overflow box(what material?). The only other that I can think of is glass.

[glazer]

Table saw or circular saw to cut the stuff.... more teeth to the blade the better but DO look for a TCG marked blade (triple chip grind). If you are "overgluing" the edges as opposed to making them flush a laminate router (or a larger one, I use and prefer the router table set up) with a carbide flush cut bit will work fine.

With the right blade you will have very minimal work to do to the edges of the material to get a good bonding surface. I made up a little jig that holds a stiff utility knife blade... block of wood with a dado cut in it the thickness of my material and the blade fits in it so it sits just a HAIR off perpindicular to the material... few swipes with this acting like a scraper and there is no sign of any tooling marks from the saw blade.

As far as cutting teeth in it... well again I use a router table with a jig.
http://i904.photobucket.com/albums/ac249/bonsaireefs/Minibow%20returns/P1000714.jpg
You can use a dremel and there is a variety of bits that can work pretty good. Just need to run the tool on a slow speed and not force anything so as not to get enough heat built up to make a gummy mess.

Steve

[uncleof6]

uncleof6 how would you suggest to build an overflow box(what material?). The only other that I can think of is glass.


On the outside of a GLASS tank, use glass. On the outside of an acrylic tank use acrylic. I leave the acrylic work to the acrylic guys, for the most part, though I do know how to work with it, and have considerably.

Jim

[kdc527]

Thanks Glazer and uncleof6,
It is a glass tank does that mean I must use glass for the overflows or is it a recomendation what are the reasons behind using glass for a glass tank? If i keep the internal overflows can i use acrylic, or will there be a bonding issue I was going to have a buddy who is a glazer attach the overflows He says aquarium grade silcone will do the trick but these will be the first ones he has installed.

[uncleof6]

Acrylic and silicone do not bond well together. Inside the tank is ok, but outside the tank, use glass only. Since there is no such thing as "aquarium grade" silicone, that could mean a lot of different things. The best silicone for the job is Momentive RTV108.

Jim

[kdc527]

Ok thanks for clearing that up for me I said aquarium grade but what i meant was momentive silicone I will make sure i purchase the rtv108 thank you again for all your help.