5' Skimmer Build in Progress

I decided to try my hand at forming a cone while I watched the football game tonight.

Here is the bottom of the form.

87029formbase.jpg


Here is the form loaded with the acrylic.

87029formwithcone.jpg


87029intheform.jpg


Here it is out of the form.

87029coneafterforming.jpg


87029testfit.jpg


The black line that is visible is where the ABS pipe melted onto the acrylic while I was shapeing it.

I still need to make a jig for cutting the flange for the cone as well as the flange for the skimmer body.

I also have to make a decision on attaching the riser neck to the cone. Do I want to just cement it on the cone as a single piece, or do i want to add a break down joint there as well. I will already have a joint at the bottom of the cup and at the base of the cone...

Dale
 
I'm probably blind so if you already told this sorry. How did you heat the sheet before forming to make the cone? I want to try this and it seems you have it worked out so any and all details you can give is greatly appreciated.

Thanks in advance
John

BTW, looks great.
 
Many of us heat the acrylic in our ovens; 325F is optimal. Others on this site have warned that heating acrylic causes it to release gases which can explode. It would seem that the chances of building these gases to the lower explosive limit (LEL) is unlikely since I've not heard of anyone having an explosion.
 
Against the advice of the pros, I used my oven. I set my oven to 375. I formed it over many cycles. I heated and shaped. Repeat. I kept this up until I achieved the final shape. One mistake I made was using 3" ABS pipe as the center pivot. After fighting with teh piece for a while I put the entire thing in the oven. During my haste, the pipe softened and attached to the acrylic. I now have a non centered ring where one of my early formings stuck to the sheet. It may be better to thoughrly heat the acrylic and shape it in one step.

As mentioned earlier, there are risk. I turned on my kitchen vents during the process.
 
Sorry to bud in... I saw that some of you are using "air stones" I just wanted to ask what is the reason you are not using wooden air stones? I have not found anything that can produce bubbles the size of wooden airstones.
 
I figured the oven was the method but hoped for something else. There is no way that my wife will let me put anything in our new oven. Oh well, really not on topic. Thanks for the info and nice job.
 
I have never used wooden airblocks. I hear they make good bubbles, but I heard that the fine pore ceramics were as good or better with exceptional life. I can not verify either at this point.

Dale
 
tinygiants et al,

I have found it is easier to form a cone by placing the entire mold assembly in the oven and heating at 325F. This allows for a constant slow deformation and produces very nice results. Of course, don't use plastic as the mold! Anyway, I hope this helps.
 
<a href=showthread.php?s=&postid=6571705#post6571705 target=_blank>Originally posted</a> by ChemE
tinygiants et al,

I have found it is easier to form a cone by placing the entire mold assembly in the oven and heating at 325F. This allows for a constant slow deformation and produces very nice results. Of course, don't use plastic as the mold! Anyway, I hope this helps.

Now you tell me!

Of course it all makes sense now. When I started this process, I had no intention of putting the pipe in the oven. I only placed the sheet to be formed in there. But I was not able to get it to form very well. So as I started to get desperate, I resorted to the pipe in the oven to let it heat and relat into shape.

Dale
 
<a href=showthread.php?s=&postid=6563024#post6563024 target=_blank>Originally posted</a> by tinygiants
I decided to try my hand at forming a cone while I watched the football game tonight.

Here is the bottom of the form.

Here is the form loaded with the acrylic.

Here it is out of the form.

The black line that is visible is where the ABS pipe melted onto the acrylic while I was shapeing it.

I still need to make a jig for cutting the flange for the cone as well as the flange for the skimmer body.

I also have to make a decision on attaching the riser neck to the cone. Do I want to just cement it on the cone as a single piece, or do i want to add a break down joint there as well. I will already have a joint at the bottom of the cup and at the base of the cone...

Dale

I am going to do basically the same thing (shape a cone). It looks like you used approx 1/4" acrylic. Once adequately heated, just how tall of a cone do you think one could make?
I was thinking of trying to make a cone that is quite tall. I imagine thicker acrylic would be necessary for a "real tall cone", but I already have 1/4" acrylic. I donââ"šÂ¬Ã¢"žÂ¢t want to waist a nice piece to experiment if I could get a little input first.
 
beacuse you have to buy or make wooden airstones and then replace them every few weeks
I've used both bought (Red Sea and Sanders) and homemade (KW) wooden air diffusors. I've also used 6" ceramic diffusores. IME on the most basic little skimmer with un-filtered air, the small air stones last at least 2 months. For the KW wood pane diffusor I filtered the air down to < 1micron. I got over a year out of a KW in one instance.

Like I said way back in this thread, Mojoreef told me that he thought the AES fine-pores out-performed the KW. I haven't tried the new AES fine pore ceramic, so I have no comparison. I do know the ceramic diffusor I tried had too much back pressure. While I respect Mojo's opinion, I don't think he's ever actually used a KW, himself.

Anyway, I think people may be leading themselves down a garden path on this wood diffusor thing. IME they don't require the frequent replacement that it is popularly believed that they do. For a skimmer the size of Tiny's, KW diffusors are a viable option, IMO. You can stick a 3" X 3" X 3" KW diffusor down a 6" pipe, and most of that is viable BPSA. Thats a butt-ton of BPSA for a few bucks cost.
 
I agree on that Howard and I will be using wood on mine. I have designed my skimmer so that the stones can be easily removed, cleaned, and replaced. It would take about 1 minute, maybe 2.
 
Howard,
What size wood diffusor would you suggest for a skimmer 10.5 inches in diameter and a mixing chamber about 58 inches tall.

Mike
 
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