DIY Skimmer and an attempt at making my own tube

"Does anyone have any suggestions as to what can I use for a seal between the flanges?"

I would suggest going to a hardware store & buying a sheet of neoprene ( that's what I use ), but your opening is too large. I think Ive only seen up to 12X12.

A roofing supply may have a scrap of the stuff you would need to cut a gasket that large.

Stu
 
I have purchased large rubber sheets (neoprene, silicone, etc) from eBay. Yes, roofing supply houses, shower pan liners and pond liners are all candidates as well but may be a bit too high of a Durometer for this application. You are looking for something less than 70A Durometer.

That said:

The large the surface area of the gasket, the more pressure it takes to seal.

In other words, given the same flange, an O-Ring takes a fraction of the clamping force as a flat gakset.
 
Did a search and it is hard to find silicone sheets with the dimensions I need without getting to crazy on the price, so neoprene mite be it.
On another note, I thought of using plastic dip (the stuff you use to wrap tools like handles of pliers) by building up a few layers on both sides of the flange, but did a little test this stuff is soft for a couple but keeps hardening with time, I’m afraid it will fail in time.
Also thought about using surgical tube, having a continuous tube that will go around let’s say two or three times.
Any thoughts on this?
 
What not just route an O-ring groove (or a primary and backup groove) and buy round or square o-ring stock from mcmaster?
 
I believe they only go up to 26” diameter, I’m at 23” but because of it being square (didn’t do the calculations) I would need something around 30” in diameter and if I find them, they would probably be very pricey
 
If you cut it to length, Stu, it wouldn't be continuous. How would it seal?

How about a very thin bead of silicone? Let it dry and then it will be rubbery like a gasket. Best of all it won't glue each piece together. If it fails, scrape it off.
 
Last edited:
<a href=showthread.php?s=&postid=13844027#post13844027 target=_blank>Originally posted</a> by lakee911
If you cut it to length, Stu, it wouldn't be continuous. How would it seal?
Click to expand...

You have to order the splice kit. Its listed on the same page. You cut it to length, splice it together, you have a continuous O-ring.
 
I would prefer something that will maximize surface contact and support, the sheets allow for this, you see the flanges are ½ “ extrude acrylic (a mistake here should of bin cast, but it is what I had) I noticed there is a bit of flex on them, I know once they are glued to the box they will gain a little strength, but I’m afraid by using an o ring type of gasket, this will create a pivot point that will stress the acrylic.

Thought of making this, it will give support and will eliminate the need for countless nylon screws and holes (you know how it is, after an hour of making holes, you are about to drill the last hole and the whole piece shatters) If I use two pieces of metal, pre drill them, dip them in plastic dip for corrosion protection, then attach them with maybe 4 titanium screws over the flanges.

f10.jpg


Also out of curiosity what do you guys think of this stuff to make a gasket, click on video #1 they use hobby mold 150 and on the top left side (silicon rubber) they have 160 that is 45 shore very flexible.
http://www.hobbycast.net/video.htm


.
 
i use a rubber mat.....one that is used for a sandblast mask.....it has a adhesive on side kinda help's when making gaskets.....it normaly would be used for masking off a piece of glass or acrylic while sandblasting........it is about a 1/6" thick rubber.....with the adhesive you can peel the paper off the back and stick it where you want it and drill cut or what ever you want to do with it...........works like a champ.......i have used it many times and never had a leak.......
 
You are going to have a hard time casting your own gasket. You will be much better off with an O-ring or flat gasket. As I mentioned, flat gaskets take significantly more clamping pressure to form a seal.

I would also strongly advise against nylong screws or bolts. They stretch and are hard to losen, if not murder on the fingers. Use SS or Ti. Take it a step further and use studs and Wing nuts.
 
Ok, that hobby mold was just plain cool! I know, I'm easy to please. :D

Bean has a point. If you're concerned about an o-ring creating a pivot point, you probably have less to worry about going that route as oppose to a flat gasket and having to crank down on it to get a seal.
 
Esquare.... Bean has a point. If you're concerned about an o-ring creating a pivot point, you probably have less to worry about going that route as oppose to a flat gasket and having to crank down on it to get a seal.
Click to expand...

I don't need to crank on anything to get a good seal.. When I take the skimmer all down to clean.. I have to crank on the two peaces to get them apart. "To break the seal.."
 
I have had very good luck with the 1/4-20 nylon bolts you get from HD. I keep tons of them around. ( not to mention I have BOX FUL of 1/4-20 taps ;-)

When I need to tinker with Acrylic, I will drill & tap rather than glue unless it needs to be water tight.

Just be prepared, HD doesnt stock that many at a time. There have been a few instances I have gone in and bought all they had. ;-)

Stu
 
<a href=showthread.php?s=&postid=13845656#post13845656 target=_blank>Originally posted</a> by lancepender
I don't need to crank on anything to get a good seal.. When I take the skimmer all down to clean.. I have to crank on the two peaces to get them apart. "To break the seal.."
Click to expand...

The wider the gasket, the more pressure is needed to force a seal. The force required is s direct function of the contact area between the face and the gasket.

A FLAT 1/16 "0-Ring", 16" long would have 1 square inch of surface contact. So applying 10 pounds of force to the flange would create a sealing force of 10 P.S.I.

A gasket 3 inches wide that covered the same 16" face would have ~48" of contact area. The same 10 Pounds of force on the flange would only create 4.8 P.S.I of sealing force. To get 10 P.S.I of sealing force, you would need 480 pounds of force on the flange.

If the flange is not sufficiently flat, then the flat gasket will not evenly compress, and therefore MANY more pressure points (bolts) will be needed to distribute the load.

We are not working with high pressure devices here, there is no reason that a flat gasket is needed or worth the trouble.

I made the mistake of using a flat gasket on my 6' skimmer base because I did not want to wait for the 0-ring stock to arrive. The amount of torque required to get a seal is crazy.

As for the Nylon bolts.. to each their own. I will never use Nylon thumbscrews on a project again. SS does not stretch or break and is easy on the fingers :)
 
I see Bean’s point, guess I’ll go with the silicone o ring cord from sturgray's link.

Shookbrad, It is hard to say, acrylic prices go up an down and I used a few left over scraps that I had, but for this size your looking at 2-sheets of ¼” and half a sheet of ½”
If you take this rout (having the square box as the outside) the inner cylinder doesn’t have to be ¼” it can be real thin stuff and you wouldn’t need to bend it probably wrap it self by hand, when I’m done I will try to post a round figure of the cost.

Esquare, yah, I can see some one here on the DIY forum using that method to build a impeller or something along those lines.

So what do you guys think of using steel bars as clamps? Each flange is about 104 lineal inches x 2 if I space the screws 3” (I would dill them in pairs) that’s still about 68 holes … that’s a lot of firkin holes to make and from past experience, that’s 68 chances of screwing up and at the same time would give me extra support.
 
You must log in or register to reply here.

Similar threads

ClownBubbaJoe
Skimmer, TALL skimmer vs short under cabinet type ?
Replies
13
Views
655
BeanAnimal
B
B
55 gallon Tank Soft coral and fish under regular LED light
2
Replies
24
Views
2K
Misled
Misled
Paul B
Why do we find this stuff so facinating?
Replies
3
Views
1K
Timfish
Timfish
jtrasap
FS: 150g deep dimension tank, a couple sumps, media reactor, and a skimmer
Replies
0
Views
511
jtrasap
jtrasap
R
AquaOne ReefSys 180 Build 2022
Replies
4
Views
1K
Plastik0cean
Plastik0cean
Back
Top