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#51
03/28/2005, 08:00 PM
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I only had my oven set to 300 deg F. It seemed to work pretty well for me. It only took 10-14 minutes to get hot enough to form. It was just plyable enough to force my shape and then it hardened within 30 seconds or so. I didn't get ANY fumes that I could smell whatsoever from mine and I didn't even have any ventilation into my kitchen...all doors to the house/kitchen closed. I used 1/4" acrylic. I wonder if I didn't get any fumes because I didn't get mine as hot...
I'm sure you get more fumes the hotter you get the acrylic. So the SAFEST way to do this might be to only heat to 300-310 deg F and then do some type of "force" forming if possible. The problem with the gravity method is that you have to get the acrylic hotter and it also takes longer to get the heavy object hot as well. |
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#52
03/28/2005, 08:48 PM
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just an f.y.i.
if you dont heat the acrylic enough it will craze when you solvent cement it together. too hot and it will bubble and too cold and it will craze. i would keep it around 340 to 350. internal stress will show up in time too if it is not heated properly. in time it also absorbs water and it will craze due to internal stress if not heated properly. this is from the cyro industries website FORMING TEMPERATURE (°F) ACRYLITE® FF acrylic sheet 290-320 ACRYLITE® AR acrylic sheet NOT RECOMMENDED ** ACRYLITE® GP acrylic sheet *** (what is used for aquariums)*** 340-380 ACRYLITE® GAR acrylic sheet NOT RECOMMENDED ** ACRYLITE® SG acrylic sheet 270-350 ACRYLITE PLUS® acrylic sheet 270-350
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a wise man once told me.... " there is no right way to build a reef tank but there is alot of wrong ways to build a reef tank". |
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#53
03/28/2005, 09:10 PM
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Quote:
No, you really have to push hard for it to form and it bounces back so you have to hold it as it cools to keep the cone/taper. I made a second pc. with all new molds (2 pcs. of wood) and a bigger pc. of acrylic and it turned out almost perfect. So it just takes a little practice and any one should be able to do it. As far as fumes go the only thing I smelled was the plywood starting to burn. When I took the wood out of the oven it was a little darker but not scorched at all. Keep a fire ext. close by. |
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#54
03/28/2005, 09:18 PM
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why not find a plastic bowl or a top of a cookie jar something that already has a slant in it ?
just make the hole for the riser and trim the edge to the size of the tube, just a thought 
__________________
Here... take this astronaut dipper so you can spend more time next to your tank. |
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#55
03/28/2005, 09:27 PM
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My first thought was an oil funnel modified like you said, BUT and I think I can speak for most people here and it is that I/we are in pursuit of the "perfect" DIY skimmer, one that rivals any manufactured unit in both function and style.
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#56
03/28/2005, 09:44 PM
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http://www.freefreeusa.com/innovision-servingware.html
this is just a example but by doing a better search I believe one could come up with a good usable shape
__________________
Here... take this astronaut dipper so you can spend more time next to your tank. |
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#57
03/29/2005, 09:16 AM
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Definitely try to find the data sheet on the acrylic you are using. Optiplex which I picked up at Home Depot said the ideal temp for forming was 320, but that took way too long. So I experimented with 325, but 330 worked best.
Very close to the 340-350 that spazz recommended. Maybe on my next piece I try in the following weeks. Most of the fun is just seeing if you can actually accomplish the project. |
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#58
03/30/2005, 09:13 PM
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I thought the fumes only were released when the acrylic bubbled (too hot)?
If it gives off fumes when heated, then its chemical makeup is changed - ie: something is evaporating out of it. What effect does this have on the acrylic? I would like to know more about this. I have heat bent lots of sheet, and once made a half cylinder nano by heating a sheet in a commercial gas fired convection kitchen oven. I set it to about 340, waited for it to droop and layed it over a piece of 12" pvc pipe. Never smelled any fumes, even when occasionally overheating a bend. Not to say it wont happen, but just my experience.
__________________
"Not cheap, but silent and absofrickenlutely no bubbles" "Be sure and wear a speedo lest tangs nest in your britches" |
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#59
03/31/2005, 01:34 PM
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Quote:
 ) but if you create your own odorles deadly gases (another fart joke opportunity!) by heating acrylic, then you won't have any handy indicators to protect you!Just keep it in mind when you do this that these things CAN happen (just cuz we don't have an anecdote that says it did, doesn't mean it didn't) and take the proper precautions (fire extinguisher nearby, open windows, kitchen exhaust fan on, extra fan, keeping an eye on it...etc, etc...) V
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Quality friendship ... at rock bottom prices! |
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#60
03/31/2005, 03:41 PM
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great points.
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Eric |
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#61
04/13/2005, 09:42 PM
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I just used the heat gun method on a test run , since we do alot of tube shrinkage where we work , i took one of the guns . still had todo the sammich method , and used a few 2x2's to make it high enough to get the heat gun under it. I then took a foot of lead or steal or something ( was damn heavy ) and was like 3 inches or so in diameter ( doesnt matter since this is just practice , i have a cast formed A&E tech collection cup im going to try to implement into my skimmer ) any way , i placed the metal rod dead center and heated below , making sure to move the gun around just a little so i wouldnt fry one area. , took about 6 min for it to start squishing down and made about 2 inches of progress.
There is bubbling on the very bottom\top ( depends how you look at it ) but this portion is cut out anyway . we use high grade heat guns here but i used a crappy one just to test and it worked awesome . I have my shirt up right now and im pressing my gelitanous cube of a gut into it , Its pretty sweet, look likes a peach jello mold. check ebay for heat guns , they are pretty cheap. all they are really is modified hair dryers  or y ou could buy a leister heat gun and do pvc welding for those diy jobs also ( saving up for one of those my self , i want those nice pvc weld seams )
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#62
04/13/2005, 09:51 PM
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thats just wrong.
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Eric |
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#64
04/14/2005, 12:52 PM
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I wonder if it would work to just take a piece of flat acrylic glue it to the end of you pipe, take a piece of 2" or 3" tube which ever you are using for your riser, however much longer than the body of your skimmer that you wanted the slanted section. Center the body with acrylic glued to it over the longer riser tube where it balances, and heat with a heat gun. The weight of the body should pull it down and make a funnel shape.
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#65
04/14/2005, 05:59 PM
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here is some of the new and improved skimmer reducers i have completed. there not quite perfect yet. they have some blemishes to the acrylic. i have to improve the mold a little more and make some more.
 
__________________
a wise man once told me.... " there is no right way to build a reef tank but there is alot of wrong ways to build a reef tank". |
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#66
04/15/2005, 09:30 AM
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spazz,
anyway you can make those and keep a flange on the bottom? Once you glue them to your body...no more maintenance inside your skimmer body...  Unless you just plan to glue them to a flange...but wouldn't it be easier to leave the flange in the first place...kind of like how I made mine? Just curious here... Looks like your getting a nice shape though! |
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#67
04/15/2005, 10:37 AM
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On the larger euro-reef skimmers 8" and above you can fit your hand through the spears union. On the 6" models you can use a toilet bowl brush to clean the inside. It hasn't really been an issue for me.
__________________
Progress is made by lazy men looking for an easier way to do things. |
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#68
04/15/2005, 08:06 PM
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Quote:
__________________
a wise man once told me.... " there is no right way to build a reef tank but there is alot of wrong ways to build a reef tank". |
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#69
04/15/2005, 09:40 PM
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Quote:
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#71
04/16/2005, 09:03 AM
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Spazz
Not to hijack the thread, but I machined these out of 1" acrylic on the CNC at work, I'm thinking about tossing the bottom on the lathe and cuttimg 2 grooves in it for o rings then the skimmer body can slide down over it and be removable if I ever need to get inside for maintenance. http://reefcentral.com/gallery/showp...t=1&thecat=500 http://reefcentral.com/gallery/showp...t=1&thecat=500 |
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#72
04/16/2005, 10:18 AM
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Quote:
__________________
a wise man once told me.... " there is no right way to build a reef tank but there is alot of wrong ways to build a reef tank". |
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#73
04/16/2005, 10:20 AM
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Quote:
__________________
a wise man once told me.... " there is no right way to build a reef tank but there is alot of wrong ways to build a reef tank". |
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#74
04/16/2005, 11:17 AM
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the base I was originally going to weld to the body with some #16, but I got to thinking about making it removable, might not be worth the trouble.
the reducers will be vaccum formed at work. yeah they need to be smooth or every little imperfection will form right into the acrylic. yeah I still need to flame the top cap. |
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#75
04/16/2005, 01:40 PM
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This method was previously used to form a jet nozzle from a 3/4" ID piece of PVC... and I thought, why not try it on acrylic??? It worked great for me. VERY simple and VERY interesting, a neat way of learning about acrylic's elasticity when heated. Mistakes aren't a big deal because the process doesn't take long at all and 2-3 inches of material might be wasted.
PROS: 1. There are hardly ANY fumes produced (if any at all). Reduces fire hazard potential if you are using an electric stovetop. 2. Takes 15 minutes, very fast thermal forming method. 3. Requires no mold-fabrication whatsoever. 4. You don't have to worry about the wife coming home and asking, "what's that smell" and/or "what have you been using my oven for?" An adequate term to describe the process would be Liquid thermal forming. How it's done: I used an acrylic tube and flared the end over a tapered juice glass (for a slow taper) and a small glass sauce bowl (to aggressively flare out the bottom end). This grealy simplified matters as I only needed to hold the tube and SLOWLY apply pressure to it until I achieve the desired flare-out. Use vegetable oil for cooking, preheat the oil @ around "medium" or 1/2 way on the dial of your stove top. Insert a pre-determined length of the acrylic needed to be formed into the oil for 30-60 seconds or however long it takes for the acrylic to become pliable(rubbery-feel). Using a cereal bowl, shotglass, or whatever GLASSware that has a similar profile that you'd like to have, lightly & slowly press the acrylic tube over the piece of glassware until you feel a slight resistance from the acrylic. Then STOP! Keep it pressed for and let it cool off for 1-2 minutes and the acrylic should be cool enough to keep the new shape you've just given it. If you want more of a flared profile, just repeat the process until you reach your goal. It works... I made a 2" I.D. tube flare out nicely to a perfectly flat 4" circle. It took 2 tries though because the 1rst try I pushed the tube too fast and the outside edges of the flareout developed surface cracks. SLOW AND EASY does it as well as several heat & press steps. It took me 3-4 steps to get the flare I wanted without producing surface cracks. Using a tube to create a flared profile was much easier than a flat piece of acrylic for me. I only preheated 1.5-2 inches of tube length in the heated oil out of a total of 10" of length which gave me 8" of tube to hold onto with my bare hands. No special gadgets, just veggie oil, a small sauce bowl and a cooking pot! If you desire a flat surface on the OD edges of your flare, that's simple too... preheat just the outside edge of the flare and lightly press it onto a smooth flat surface. This gives you a good "lip" to attach your collection cup's cylinder onto. My un-proven theory on the low-no fume emission is the oil absorbs MOST of the gases... however there IS ALWAYS a fire hazard risk involved when dealing with heat and materials of this nature. I kept the windows open anyways, and didn't observe any fumes. The times and temperatures i've given will vary depending upon type & thickness of the acrylic you use, of course. I used 2" I.D. 1/8" wall thickness extruded acrylic. Don't use the oil afterwards to cook food with... or your insides will expand and you will transform into something that resembles Jaba the Hut.  I wrote this in haste, gotta gooo, and i hope this helps someone! |
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