Bootlegger
New member
So I decided to make a frag rack a year or so ago for my 28 gallon nano. I made it out of 3/8 acrylic. It's worth sharing as I already had this written up on another site...quick cut and paste. Anyway, I call it El Swiss Cheese. Enjoy.
El Swiss Cheese - Final Product
Yes, I know, there are very many DIY frag rack instructions out there. Anyway, here's one more!
I've included my design because it is a sleeker, more refined alternative to the egg-crate design.
And ---- this design overcomes some of the problems people have had with using rare earth magnets in their frag rack design.
Parts list:
3/8 inch Acrylic (or ABS Plastic Sheet)
1/2 x 1/8 inch round, rare earth magnets (Home Depot Harbor Freight both sell them cheap)
1/2 inch forstner bit, preferably a quality high-carbon one. I got a whole set from Harbor Freight on the cheap.
*Loctite 2-part Plastic Epoxy (Home Depot or Lowes...or any hardware store).
Tools List:
Small Drill Press (or hand drill)
Heat gun (or propane torch)
Rubbing Alcohol
220 Grit sandpaper
*Loctite plastic epoxy makes a strong bond to Acrylic, which silicone and superglue can NOT do. When used correctly, it makes a permanent, watertight seal that is reef-safe. I know because I used it for years for gluing parts on custom calcium reactors and protein skimmers without failure.
Instructions:
Step 1: cut your 3/8 acrylic to size, preferably a rectangular strip. Warning - don't go too long or too wide as this will mean you will need more magnets to hold all the weight.
Step 2: bend your acrylic strip. I'm not going to get into bending acrylic because there are so many videos on YouTube that show you how to do this. The bottom line is you need to bend a right angle (90 degrees or so) on your 3/8 acrylic strip using the heat gun.
Step 3: drill mounting holes on the side of the acrylic you want to mount your plugs. I use my 1/2 drill forstner bit as it doesn't crack, split, or grab the acrylic. As far as hole spacing, this is for you to decide. *See my notes at the bottom.
Step 4: drill 1/2 recesses in the acrylic with your forstner bit for embedding the magnets. You will have to drill a little more than the thickness of the magnet, which are typically 1/8 inch thick. I usually go about 1/4 deep, which allows the magnets to sit down a little. A drill press makes this fairly easy and repeatable. Doing by hand is possible but takes a little finesse. Note: unless you grind down the top of the forstner bit, it will cut a small whol all the through the acrylic. If it does, you can fill this with epoxy glue during the gluing process.
Step 5: lightly sand recesses with sandpaper and then clean with alcohol.
Step 6: mix epoxy glue. Swap a light layer of epoxy into holes. Insert magnets into recess and then backfill remaining void/space on top with more epoxy glue.
Step 7: let dry for 20-30 minutes in warm place.
Step 8: sand both sides of acrylic smooth. Unless you are an impossible perfectionist, sanding on both sides will be necessary to smooth out the epoxy. I prefer to use the coarse sandpaper and sand under running water (this will scuff up acrylic by the way). For those who want to keep the acrylic looking perfect, you could also use a file or drywall sander as the epoxy is softer than acrylic, i.e. you will take a lot of epoxy off but leave the acrylic unscathed. I like to sand the acrylic to slightly opaque as I think it looks nicer while also allowing light to pass through
Step 8: wash with soap and water
Step 9: put in your fish tank and attached rare earth magnets on the other side of the glass. Since the round magnets are axially magnetized, they will line themselves up.
Step 10: put in coral frags and enjoy!
*Additional notes: I drilled many, many holes in my acrylic to lighten it up as 3/8 acrylic is heavy. It basically looks like swiss cheese but I kind of like it.
Embedded magnets - top side (away from glass)
Magnets imbedded - bottom side (what's against the glass)
Rare earth magnets for reference. Three are stuck to the embedded magnets to test how well they line up.
In the water view - rare earth magnets on outside of glass holding it up
Pros:
Easy to build
Cons:
Need bigger, more powerful rare earth magnets for tanks thicker than 3/8s
Lessons Learned:
Use bigger magnets. Perhaps use router to route channel out for the larger, rectangular magnets. I would also probably sandwich the magnet between two pieces of acrylic as the epoxy air bubbles are hard to deal with.
El Swiss Cheese - Final Product
Yes, I know, there are very many DIY frag rack instructions out there. Anyway, here's one more!
I've included my design because it is a sleeker, more refined alternative to the egg-crate design.
And ---- this design overcomes some of the problems people have had with using rare earth magnets in their frag rack design.
Parts list:
3/8 inch Acrylic (or ABS Plastic Sheet)
1/2 x 1/8 inch round, rare earth magnets (Home Depot Harbor Freight both sell them cheap)
1/2 inch forstner bit, preferably a quality high-carbon one. I got a whole set from Harbor Freight on the cheap.
*Loctite 2-part Plastic Epoxy (Home Depot or Lowes...or any hardware store).
Tools List:
Small Drill Press (or hand drill)
Heat gun (or propane torch)
Rubbing Alcohol
220 Grit sandpaper
*Loctite plastic epoxy makes a strong bond to Acrylic, which silicone and superglue can NOT do. When used correctly, it makes a permanent, watertight seal that is reef-safe. I know because I used it for years for gluing parts on custom calcium reactors and protein skimmers without failure.
Instructions:
Step 1: cut your 3/8 acrylic to size, preferably a rectangular strip. Warning - don't go too long or too wide as this will mean you will need more magnets to hold all the weight.
Step 2: bend your acrylic strip. I'm not going to get into bending acrylic because there are so many videos on YouTube that show you how to do this. The bottom line is you need to bend a right angle (90 degrees or so) on your 3/8 acrylic strip using the heat gun.
Step 3: drill mounting holes on the side of the acrylic you want to mount your plugs. I use my 1/2 drill forstner bit as it doesn't crack, split, or grab the acrylic. As far as hole spacing, this is for you to decide. *See my notes at the bottom.
Step 4: drill 1/2 recesses in the acrylic with your forstner bit for embedding the magnets. You will have to drill a little more than the thickness of the magnet, which are typically 1/8 inch thick. I usually go about 1/4 deep, which allows the magnets to sit down a little. A drill press makes this fairly easy and repeatable. Doing by hand is possible but takes a little finesse. Note: unless you grind down the top of the forstner bit, it will cut a small whol all the through the acrylic. If it does, you can fill this with epoxy glue during the gluing process.
Step 5: lightly sand recesses with sandpaper and then clean with alcohol.
Step 6: mix epoxy glue. Swap a light layer of epoxy into holes. Insert magnets into recess and then backfill remaining void/space on top with more epoxy glue.
Step 7: let dry for 20-30 minutes in warm place.
Step 8: sand both sides of acrylic smooth. Unless you are an impossible perfectionist, sanding on both sides will be necessary to smooth out the epoxy. I prefer to use the coarse sandpaper and sand under running water (this will scuff up acrylic by the way). For those who want to keep the acrylic looking perfect, you could also use a file or drywall sander as the epoxy is softer than acrylic, i.e. you will take a lot of epoxy off but leave the acrylic unscathed. I like to sand the acrylic to slightly opaque as I think it looks nicer while also allowing light to pass through
Step 8: wash with soap and water
Step 9: put in your fish tank and attached rare earth magnets on the other side of the glass. Since the round magnets are axially magnetized, they will line themselves up.
Step 10: put in coral frags and enjoy!
*Additional notes: I drilled many, many holes in my acrylic to lighten it up as 3/8 acrylic is heavy. It basically looks like swiss cheese but I kind of like it.
Embedded magnets - top side (away from glass)
Magnets imbedded - bottom side (what's against the glass)
Rare earth magnets for reference. Three are stuck to the embedded magnets to test how well they line up.
In the water view - rare earth magnets on outside of glass holding it up
Pros:
Easy to build
Cons:
Need bigger, more powerful rare earth magnets for tanks thicker than 3/8s
Lessons Learned:
Use bigger magnets. Perhaps use router to route channel out for the larger, rectangular magnets. I would also probably sandwich the magnet between two pieces of acrylic as the epoxy air bubbles are hard to deal with.
