OK I need help

[tat2z_21]

OK now I need help. I have tried to master the expertise of building a simple sump/refugium. I am building them with the thickest acrylic I can find from my local home depot. .220. I think the blade I am using on my table saw is not cutting properly and it leaves tooth marks which ends up leaking when I seal with my weld on 3. So I water check my creation and it leak checks fine. I move it into the fishtank area and both of them have leaked. I can not seem to get this right. Can somebody out there please tell me how to do this. At this point it would have probably been cheaper to just go out and buy one. But I would really like the satisfaction of building one myself.

 

[ziggy]

I have done some acrylic work BUT I am no expert. I believe that you are using a runny form of glue that may not be filling in all the "tooth" marks. You may want to try #16 which has a thicker consistancy. I also test my creations for 24 to 48 hours with 10% more water than it will hold normally in the garage. You know a blow-out will happen at 3am in the morning or while your at work. Murphy's Law

It may be ugly and it may be more expensive but you made it and you will know it better than something you bought at the store and you'll love it a whole lot more!
Good Luck
Chad
Here is a great diy link

http://www.melevsreef.com/acrylics/sumps/f/sump_f.html

 

[mfinn]

How about going to a place that sells acrylic, such as Tap Plastic or Keltech and ordering precut pieces that are ready for gluing. Have them prepare the acrylic edges and get some thicker material at the same time.

 

[tat2z_21]

That is what I am coming up with. I really want to learn how to work with acrylic, so on that note I will be ordering a few pieces of pre cut and ready to weld acrylic. Another 200dollars later and I will have this piece of art. (hopefully)

 

[Holygral]

I built my sump 2 years ago and actually dropped it in my driveway and cracked it just as it was finished. And I still have no leaks. I cut all my pieces on a fine tooth table saw, used Weld On 3 or 4 and filled the seams after that with the thicker glue type 16. I will build another one when I upgrade later year, and I will do it the same way.

 

[freetareef]

i always hear a fine tooth saw blade is a must, with weld on 16.

 

[tat2z_21]

Well I do have the fine 200 tooth blade, 10" table saw blade, I I just found out that a good sanding after cutting will help eliminate thet gaps. So I will now try to do it that way. I do not have the weldon 16, I have weldon 3. So I have to purchase the weldon 16 and I will get back to you with an update.

 

[Blazer88]

Weld on #16 worked great for my extremely sloppy edges when I made a top-down photo box. I cut the 1/4" acrylic with my sliding chop saw with a blade meant for wood, I had chips galore. #16 was thick enough to cover up the gaps and everything sealed just fine. You might want to give that a shot.

 

[mfinn]

How big of a sump are you going to build?

 

[jrowlan]

Make sure you use a fine-tooth carbide blade made for laminate and plastic. The pitch on the teeth is less aggressive than a wood-cutting blade. What you want is to wear away the plastic rather than chip it away.

After cutting, you need to scrape the edges. I use a hacksaw blade mounted between 2 lengths of 1x2 so 1/2 of the back side of the blade sticks out about half-way. I mount this in my vise and pull the plastic edge perpendicular to the blade. Check often to make sure you aren't gouging the edge. You can put a slight bevel on the edges, especially if you are using #16. Melvsreef is a good resource. Last I checked, he bought an inexpensive planer to do all of his edges. One pass and you are done.

 

[tat2z_21]

Sweet, I really do appreciate all of your guys information, I think that i am just going to break down and by one. I have enough 1/4" plexi here to practice with so that I can fine tune my acrylic working skills. I was also told that running your blade in reverse helps. Has anyone ever heard of that.

 

[JPG@CFI]

Whoever startedd the rumor to run a table saw blade in reverse, needs a caning! Get the right blace, cry once, and move on. Then buy a few good Whiteside router bits and a router, and cry somemore. The buy some wed/dry sandpaper. This is where it all started for me 16 years ago. Good luck!

 

[BrianB]

To sum up the cutting blade selection here goes: The blade should be at least 80 tooth (for a 10" blade) 2° Negative Hook - Modifed Triple Chip (MTCG) Grind
and carbide tipped. I use Amana blades and router bits but they are very expensive. http://www.amanatool.com/circular-saw-blades/non-melt-lb86401.html The Freud http://www.rockler.com/product.cfm?Offerings_ID=2360&cookietest=1 blade is also good. For a one time project any melamine blade with 80 teeth will work just fine. The important part is to use a zero clearance blade insert and blade stabilizers to reduce chipping. A slow and steady feed rate is also important for the same reason (and to avoid melting).
That being said, the most important part is how you prepare the edge for bonding. I use a jointer and that is by far the easiest and I think the best way to do it. You can scrape and sand the panels, but it is just easier to use a jointer. Melevsreef is a very good source of info for this and he describes the scraping and sanding method.

 

[BrianB]

As far as the bonding, weld-on 16 has it's uses. It is very good at bonding poor quality edges and hard to access places, but is very sloppy and prone to lots of bubbles. Weld-on 3 is a fast set liquid solvent and weld-on 4 is a medium set solvent. Unfortunately they quit making weld-on 5 (thanks California EPA) but there are some other manufacturers that make similar products. ( Plex-weld ect....) Once again Melevsreef gives very good advise on this subject. However, he doesn't talk about weld-on 40. 40 is a two part, epoxy like cement that bonds acrylic to itself and many other "plastic" materials. 40 is by far the best "fix all" bonding agent. Here are some links
http://www.ipscorp.com/industrial/indprodbultnpdf/PB40.pdf
http://www.rplastics.com/weldon40.html

 

[ziggy]

Cool info on pexi and glue.

 

[tat2z_21]

Well Brian B You may have become my new best friend. Thanks for the help. All of your information is very helpful.

 

[BrianB]

You are welcome. If you need anymore help just pm me or post questions here.

 

[bbl_nk]

Definitely look to buy a blade made for this. i picked one up for my 5 3/8" circ from my local Ace for $7. I didn't use the hacksaw blade approach but used a unility knife blade, a file and a srap peice of acrylic wrapped with sandpaper as a block. Just be careful not to round the edges. I broke down and just ordered a cheapo router table from Harbor Freight so I can get nice clean edges and do some more intensive circle cutting for my DIY skimmer and DIY media reactor.

I love acrylic, it is fun for sure and I would recommend starting small. I started with a HOB overflow and learned quite a bit with that process. Also check out Tap Plastics and usually you can get some scrap peices for cheap. I picked up about 30-40 lbs of scraps for about $10 and I have a lot of little projects coming out of that I have also seen larger peices of scrap for a few bucks, depending on the store. With scratches, you can buff them out pretty easy and for sumps and behind the scenes stuff, a little scarring just ads character

Good luck!