posted
Thanks for the tutorial. You have helped me more than you know . The tips you gave work great . Just have 1 question though . How far apart do you usually space the screws when drilling thru 1/2" plexi for veiwing windows on a sub box that will hold 15's? I used gaskettape that i got from select products around the edge over my screw holes . Should i also use silicone to seal around the edge of the plexi? Should i be wearing a respirator or mask when cutting plexi?
quote:Originally posted by AK1: How far apart do you usually space the screws when drilling thru 1/2" plexi for veiwing windows on a sub box that will hold 15's?
I would recommend that you try and use 3/4" Plexiglas stock, if the 15 has got some power behind it, it'll stress a piece of 1/2 " rather easily.
In either case I try to keep the spacing between mounting holes in the 2" to 3" range.
I used gaskettape that i got from select products around the edge over my screw holes . Should i also use silicone to seal around the edge of the plexi?
I use a line of foam weatherstrip tape 1/4" thick, and 1/2" wide. I run a line around the entire mounting surface, making sure to "connect the dots", from screw hole to screw hole. Then pushing the screws through the weatherstrip and tightening all of the screws in an alternating pattern, kinda like the bolt sequence on a cylinder head.
Should i be wearing a respirator or mask when cutting plexii?
A respirator is a good idea, the fumes released when cutting Plexiglas are noxious(will cause nausea), but the effects pass quickly. I usually recommend that you have a well ventilated work area, or try to keep a fan around.
posted
Really 3/4" huh . Thats got to be very spendy . The plexi will be mounted inside the top of my box so i can see the back of the subs . The openings measure roughly 8"x10" , i thought that 1/2" would be strong enough . So you would still recommend thicker plexi even on a small window . The box will be sealed 2.25 cu ft with a 15w3 and about 500w. thanks for the help.
posted
WOW nice post =) I was just wondering, I have seen boxes for sell before that were made entirley of plexi, are these strong enough for spl uses and are they worth the cost over mdf? thnx in advance
------------------ That which does not kill you postpones the enevidable apollyon_rev911@yahoo.com Never underestimate the power of stupid people in large groups =) aol: apollyon9515 icq: 33226919
Posts: 424 | From: New Johnsonville, TN USA | Registered: Apr 2001
| IP: Logged |
posted
Totally plexiglas enclosures are not well suited for extended high SPL use, sooner or later something is going to crack, but they sure are pretty.
posted
hey Mabeita...props for the great post again...just have a couple questions i'd like to run past you if you wouldn't mind...everytime i see really well done plexi enclosures, they have the rounded corners and edges, seamless port mountings, and they look very uniform throughout...how do you obtain the rounded corners and makes those types of seams to disappear...what i'd imagine for the corners and edges, you'd take a router to it and then sand and polish like you described...would it be easier to work with a single piece for a single round side?...say like a 6"x6"x6" cube made from a 24"x6" piece and then 2 6"x6" pieces or would it be easier to use 6-6"x6" pieces?...know what i'm getting at?...what i wouldn't give to have you as a prof of a Fabrication/Materials class...i'm always finding great posts of yours where you explain things that i don't even think i'd ever hear in my life from anyone around me here...i want to work with plexi for a project of mine to create a cube, like i mentioned...not sure of the size yet, but i'd like to try it out before i truly attempt it...thanks in advance...all info is much appreciated...it's already more than i've found anywhere else
-------------------- Linux Airline Disgruntled employees of all the other OS airlines decide to start their own airline. They build the planes, ticket counters, and pave the runways themselves. They charge a small fee to cover the cost of printing the ticket, but you can also download and print the ticket yourself. When you board the plane, you are given a seat, four bolts, a wrench and a copy of the seat-HOWTO.html. Once settled, the fully adjustable seat is very comfortable, the plane leaves and arrives on time without a single problem, the in-flight meal is wonderful. You try to tell customers of the other airlines about the great trip, but all they can say is, "You had to do what with the seat?" Posts: 2956 | From: Tinley Park | Registered: May 2000
| IP: Logged |
quote:Originally posted by Darkness: hey Mabeita...props for the great post again...just have a couple questions i'd like to run past you if you wouldn't mind...
Everytime i see really well done plexi enclosures, they have the rounded corners and edges, seamless port mountings, and they look very uniform throughout...how do you obtain the rounded corners and makes those types of seams to disappear...what i'd imagine for the corners and edges, you'd take a router to it and then sand and polish like you described...
You're on the right track, it's best to machine the plastic into the desired shape and then proceed to sanding and polishing the edges.
A router is the best way to get there, with a small assortment of router bits and some polishing supplies, you can get some really cool edge treatments. With a small investment in a 12 volt neon light, you can really make your project come to life, just be sure to keep a supply of paper towels handy, to clean up after your drooling friends.
Would it be easier to work with a single piece for a single round side?...say like a 6"x6"x6" cube made from a 24"x6" piece and then 2 6"x6" pieces or would it be easier to use 6-6"x6" pieces?...know what i'm getting at?...
The degree of difficulty will depend entirely upon the amount of practice that you've been able to get in. For a project like the cube that you describe, I'd probably go with the six pieces, simply because they'll be easier to handle. using the "Dip and Set" method of adhesion you'll be able to get some nearly invisible joints between the pieces of your project. After the assembly is complete you can go over the edges of your project with a clean sharp router bit and follow that up with some polishing and you'll a really cool looking cube-thingy in your posession.
What i wouldn't give to have you as a prof of a Fabrication/Materials class...i'm always finding great posts of yours where you explain things that i don't even think i'd ever hear in my life from anyone around me here...i want to work with plexi for a project of mine to create a cube, like i mentioned...not sure of the size yet, but i'd like to try it out before i truly attempt it...thanks in advance...all info is much appreciated...it's already more than i've found anywhere else
Oh yeah, Professor Abeita has a nice ring to it.
No problem, if you need any more info or assistance just post again.
posted
wonderful...i've already got this post printed out from a while ago...gonna start the Mike Abeita collection of fabrication... ...hehe...like i said...never had a place to get info on any sorts of fabrication...so this is great...well..the plexi stuff doesn't sound all too bad really...just something to get used to...good stuff...thanks again and take care...i'm sure i'll find something else i've been wondering about to ask you...hehe
-------------------- Linux Airline Disgruntled employees of all the other OS airlines decide to start their own airline. They build the planes, ticket counters, and pave the runways themselves. They charge a small fee to cover the cost of printing the ticket, but you can also download and print the ticket yourself. When you board the plane, you are given a seat, four bolts, a wrench and a copy of the seat-HOWTO.html. Once settled, the fully adjustable seat is very comfortable, the plane leaves and arrives on time without a single problem, the in-flight meal is wonderful. You try to tell customers of the other airlines about the great trip, but all they can say is, "You had to do what with the seat?" Posts: 2956 | From: Tinley Park | Registered: May 2000
| IP: Logged |
posted
excelent post mabieta...just gave ya a 5 star rating any other useful tips you can provide us with..how about a long detailed tutorial on fiberglassing ect you r the man..nah but anymore plexiglass tips?
-------------------- system under contstruction Lightning audio X1.800.4 Lightning Audio X1.1000.1 Posts: 2635 | From: hilo, HI | Registered: May 2001
| IP: Logged |
posted
umm i didnt get to read everything yet just put all the info on word and saved it..but what about the fmae polishing..whats that all about???and how do you do it??thnx
-------------------- system under contstruction Lightning audio X1.800.4 Lightning Audio X1.1000.1 Posts: 2635 | From: hilo, HI | Registered: May 2001
| IP: Logged |
posted
Mabieta, Great post. I do want to add a few things.
1. If you heat the plexiglass too much, you will get bubbles in the bend. So while you are heating the piece, try bending it a little. If it doesn't bend easily, then you haven't heated it enough. I don't know if its necessary to say, but you want to take off about 1-2" off either side of the paper where you are going to bend.
2. You can clean plexiglass with alcohol (its great to get adhesive or tape residue off of it). Be warned that you do NOT want to get alcohol on an area that has been heated or flame polished.
3. Once you get the paper off, you want to get something called brilianize and spray it on the piece you are working with. Pulling the paper off creates static that attracts dust. Brillianize is an anti-static/cleaner spray that works wonders to keep it clean. Wherever they sell this should have the correct clean wipes to polish (do NOT use a paper towel, as you will scratch it).
4. Do NOT use anything besides the brillianize, alcohol or a plastic polish to clean plastic. Windex, glass cleaner, or anything else ammonia will mess up the plastic. A clean towel can be used, but the special clean wipes work fine (its a disposible cotton towel that doesn't leave lint, unlike a paper towel that is paper).
5. Flame polishing is another option for getting a clean polished edge. Might be something you have a plastic shop do if you don't have a buffing wheel.
6. When bending a large piece, consider placing a small cut on the inside of the bend to get it to bend more sharply.
7. If you are using a jigsaw, put masking tape across the bottom. The metal bottoms of many jigsaws can scratch or tear the paper.
8. If you get a tear in the paper, put masking tape over it to protect it.
9. When polishing with a wheel, try not to get the piece too hot. If you do, the plexiglass will burn and you will have the sand it over and start again. If you burn it too bad, you won't really ruin it, you might have to run it back through the saw and knock a 1/32" or something like that.
10. To save some time in sanding, you can use a sharp scraper to remove some of the saw marks on thicker pieces before you begin sanding.
11. In two years of working as a fabrication assistant, the only time I worked with a respirator was when sanding. I actually enjoyed the smell of melted plastic, and even the glue.
12. Two side tape is your friend. Most plastic shops use it for fabrication. Lets say you want to make an "v" shaped piece of plexiglass. Well, you would make a jig at the angle you wanted, two side tape it to the table, and then heat your piece, slide it into the jig, and when you are happy with the position, you would take some clamps and hold it in place until it cools. You can also use it as a guide for your router. If you want a straight line, cut it on the saw, then two side tape a straight piece on the back, use a flush cut router bit and away you go. This is how they round the edges as well. They have a rounded jig that is two side taped to the piece and then the ends are routered off. I have used it in a 101 different ways (hell, its so strong that if you leave it on a few days or weeks, you can pull formica off a table with it).
As for a flame polishing how to, I'm not sure you guys want to try. Basically, after all the work you have done, you can royally screw your pieces up. And if you want to try, be warned I believe you need a hydrogen/oxygen mix, since a propane/oxygen mix will yield too dirty of a flame. Flame polishing is the way to go, but it takes practice and lots can go wrong if you don't do it right. On larger pieces, you don't have a choice (you can't buff a large fishtank on a bench buffing wheel). From memory, if I had every tool available, I could probably get pretty far, but the flame polishing I would leave to the pros, or do regular polishing.
quote:Originally posted by OldOneEye: Mabieta, Great post. I do want to add a few things.
Mabeita, E-I
1. If you heat the plexiglass too much, you will get bubbles in the bend. So while you are heating the piece, try bending it a little. If it doesn't bend easily, then you haven't heated it enough. I don't know if its necessary to say, but you want to take off about 1-2" off either side of the paper where you are going to bend.
Bubbles yes, but if the flame is used to provide the "heat" that actually allows you to form the plastic then it's a pretty simple procedeure, just keep the tip of the flame from coming in contact with the plastic and everything will work out just fine.
2. You can clean plexiglass with alcohol (its great to get adhesive or tape residue off of it). Be warned that you do NOT want to get alcohol on an area that has been heated or flame polished.
Alcohol will do but the evaporative properties of alcohol have been less than desireable, the easiest way to ruin a really nice project is to dry out the surface of the plastic, this increases the possiblity of static build-up and the plastic becomes a dust magnet.
3. Once you get the paper off, you want to get something called brilianize and spray it on the piece you are working with. Pulling the paper off creates static that attracts dust. Brillianize is an anti-static/cleaner spray that works wonders to keep it clean. Wherever they sell this should have the correct clean wipes to polish (do NOT use a paper towel, as you will scratch it).
Most home improvemet stores will have cleaners in stock that are meant for cleaning plastic mini-blinds, this will work very well for cleaning and maintaining the desired anti-static properties of your plastic pieces.
4. Do NOT use anything besides the brillianize, alcohol or a plastic polish to clean plastic. Windex, glass cleaner, or anything else ammonia will mess up the plastic. A clean towel can be used, but the special clean wipes work fine (its a disposible cotton towel that doesn't leave lint, unlike a paper towel that is paper).
Grab-it wipes marketed by pledge work as well, dusting and cleaning without lint.
5. Flame polishing is another option for getting a clean polished edge. Might be something you have a plastic shop do if you don't have a buffing wheel.
Practice, practice, practice....
6. When bending a large piece, consider placing a small cut on the inside of the bend to get it to bend more sharply.
As long as the cut will not detract from the desired effect.
7. If you are using a jigsaw, put masking tape across the bottom. The metal bottoms of many jigsaws can scratch or tear the paper.
Better yet, if your jig-saw is a little rough around the edges, or bottom in this case, take some time to maintain your tools. File off any large protrusions from your saw's base and then use a fine piece of sandpaper to "true" the surface of the base that rest on your workpieces, then apply a thin coat of beeswax or furniture wax to lubricate the surface of the base. Once you've taken care of this, you'll get much better results from your jigsaw than you ever expected, the same can and should be done for all tools that you use to rout, cut, drill and sand.
8. If you get a tear in the paper, put masking tape over it to protect it.
9. When polishing with a wheel, try not to get the piece too hot. If you do, the plexiglass will burn and you will have the sand it over and start again. If you burn it too bad, you won't really ruin it, you might have to run it back through the saw and knock a 1/32" or something like that.
Yup
10. To save some time in sanding, you can use a sharp scraper to remove some of the saw marks on thicker pieces before you begin sanding.
Even easier, take your time when cutting the plastic in the first place, slow deliberate cuts provide the cleanest edges to begin with. If your tools are in good working order the results will show it, sharp blades give the best results, and if you can afford to get a blade that you use only on plastic, do so. The Freud LU 98, Triple Chip Grind, is by far the best blade available for cutting plastic stock of various thickness, a modest investment of $75 will get you a blade that can produce edges as smooth as if cut by a router.
11. In two years of working as a fabrication assistant, the only time I worked with a respirator was when sanding. I actually enjoyed the smell of melted plastic, and even the glue.
Exposure to fumes that are noxious and can be toxic as well, not even close to being on the top of my list of "things to do."
12. Two side tape is your friend.
Agreed.
As for a flame polishing how to, I'm not sure you guys want to try. Basically, after all the work you have done, you can royally screw your pieces up. And if you want to try, be warned I believe you need a hydrogen/oxygen mix, since a propane/oxygen mix will yield too dirty of a flame. Flame polishing is the way to go, but it takes practice and lots can go wrong if you don't do it right. On larger pieces, you don't have a choice (you can't buff a large fishtank on a bench buffing wheel). From memory, if I had every tool available, I could probably get pretty far, but the flame polishing I would leave to the pros, or do regular polishing.
posted
just a quick question...you mention the Weld-On #4 & #16 solvents...i've been looking for a place to get even a respectively similar solvent and haven't been able to find any...(except San Diego Plastics, but i don't quite need $75 worth of stuff...just like $10)...just wondering if you know of any places to pick it up...Home Depot doesn't have anything so ....ah well...but in the meantime, i'm gonna be calling a whole bunch of plastics places out here by me so...if i find somethin', i'll letcha know...but if you have an online source, that'd be great...much appreciated
Eric
-------------------- Linux Airline Disgruntled employees of all the other OS airlines decide to start their own airline. They build the planes, ticket counters, and pave the runways themselves. They charge a small fee to cover the cost of printing the ticket, but you can also download and print the ticket yourself. When you board the plane, you are given a seat, four bolts, a wrench and a copy of the seat-HOWTO.html. Once settled, the fully adjustable seat is very comfortable, the plane leaves and arrives on time without a single problem, the in-flight meal is wonderful. You try to tell customers of the other airlines about the great trip, but all they can say is, "You had to do what with the seat?"
Posts: 2956 | From: Tinley Park | Registered: May 2000
| IP: Logged |
posted
I wasn't talking about using a flame to bend, I was talking about using a heat strip like you described.
6. I guess what I meant was if you want to get a bend bigger than 90 degress, that cut will help.
7. I've seen it even with brand new stuff. That stuff is typically designed to work with would.
Furniture stuff works, as would pledge. We used silicon spray. Worked well enough. The LAST thing you want is to have a thick piece on the table and have it stick because its not slick.
9. Only a few comments, the shop I worked at had a very high quality saw, a large table to push the work onto (we could cut a 4 x 8 piece alone and not worry about anything happening once it was on the table) and we got the blades sharpened regularly. Even when we did a first rough cut with the saw, and then trimmed off 1/64" or 1/32" to get it to the spec we wanted, we still ended up with some saw marks. Working slow also leads to the plastic heating up as well, making the stuff more likely to have saw marks.
Granted, they have machines that will eliminate them, but at that time I was that machine, using the edge of a small scraper to scrape some of the saw marks off. Having done it both ways (both sanding down the saw marks, and then scraping and sanding the saw marks) I can tell you that it takes more time to sand than to scrape and sand.
Another comment. If you have an air compressor, blow off your plexiglass as you work.
As for San Diego, try Ridout Plastics. They are off of Ruffin road, between Balboa and the 52 freeway. I would look in the phone book. Have lots of supplies geared towards DIY last time I checked.
quote:Originally posted by Darkness: just a quick question...you mention the Weld-On #4 & #16 solvents...i've been looking for a place to get even a respectively similar solvent a
