Building a new OB

Paul W · « **Reply #80 on:** 4 Mar 2007, 02:14 pm »

...almost forgot. If Water Putty is still harder than you want to sand, mix some plaster of paris with the WP. Blending PP and WP gives a wide range of options.

Bob in St. Louis · « **Reply #81 on:** 4 Mar 2007, 03:49 pm »

Paul - Good info, thank you. I'll keep that in mind. However, for this project, I'm on a mission and am determined to make a huge dent in this project today and tomorrow.

John - The analytical section of my brain started this project. After screwing up a half sheet of plywood I decided to start drinking.

This method lets my "creative juices flow"....Things are going much better now. aa

Unfortunately things aren't working out to scale on my sketch. My maximum height requirement (because of interferance with the PJ screen) has kept the overall height down far enough that the "artistic-creative-swoopy-flowing" bottom half of the baffle smaller than I anticipated. The business end of the baffle (the top) has taken up most of the height. Oh well, I think it'll look cool anyway.
Maybe during one of my breaktimes today I'll post some "during the build" pictures.

How's yours going John?

Bob

Bob in St. Louis · « **Reply #82 on:** 4 Mar 2007, 03:52 pm »

....by the way, Maybe I should call these, "Bob's Beer Baffles".....

mcgsxr - Are you learning anything yet?

Bob

Bob in St. Louis · « **Reply #83 on:** 4 Mar 2007, 04:12 pm »

....By the way again.....Does anybody know if fiberglass resin will dissolve/react when coating dried expanding foam??
I thought about using the foam as a base for some of the artistic "swoopys" but I didn't know if it would "eat it" so to speak?

The resin is made by "Bondo" and lists a "proprietary resin", which doesn't say much, but also contains -Styrene monomer 100-42-5 (Mr. goo where are you?) That's the only ingredient listed. The expanding foam is DOW brand "Great Stuff" and the label says, "Great Stuff is a polyurethane intermediate which is made up of polymeric diisocyanate, polyols and hydrocarbon gas"

Bob

JohninCR · « **Reply #84 on:** 4 Mar 2007, 05:05 pm »

Bob,

Test it first, but you may be in luck because isn't the fiberglass resin a poly too?

I haven't done anything yet, except planning. Still trying to find something around the house for a wire to make a hot wire cutter. If I find something with the proper rigidity and resistance you'll be in big trouble, because I might not even need to sand to create the 2" radius roundovers I want. I'm pretty confident that I'll be listening to something tonight, even if I get a late afternoon start and don't get to use a hot wire cutter. Wait till you see the 15min magnet mount I have planned. Maybe it will be Mr. Easy aka JiffyJohn .

Bob in St. Louis · « **Reply #85 on:** 4 Mar 2007, 06:45 pm »

Clarification: The resin label says, "polyester resin - a proprietary resin". Don't know if that matters. But to answer your question, "isn't the fiberglass resin a poly too", well I suppose it is based on the "polyester" comment on the label.

"I haven't done anything yet, except planning", Come on lazy!! GET TO IT!!

Put down the pencil and paper and let the sawdust fly pussy!!

Regarding a hot wire cutter John- Years ago when I was working on cars, I was playing with a battery charger and a coat hanger. With the battery charger on HIGH, the coat hanger turned into a crude light bulb. Slightly more than a yellow light, almost white. On LOW, it was a dim orange glow. I would think if a fellow experimented with a small battery charger (maybe a trickle charger??) and the appropriate gauge solid core wire he could build a hot wire cutter. You could make a plywood framed "knife" with the wire stretched between what would look like the frame of a hacksaw or coping saw and the leads from the battery charger attachted to the ends of the wire.

But you better get cooking if you're going to listening to music tonight!!

I doubt I'll have mine "in use" by the end of the day. Maybe tomorrow, but not today.

I'm going for absolute perfection in the high gloss finish, the equivalent of a show car type gloss/sheen. From what I've read about high gloss finish in fiberglassing, I don't have the appropriate type of sander (random orbital) to properly polish the resin to a sheen. I'll have the drivers mounted in the baffles before I have the finish I want, I have to save some cash to buy the sander.

Breaktime is OVER, back to the grindstone

Bob

Russell Dawkins · « **Reply #86 on:** 4 Mar 2007, 07:48 pm »

I always thought that you needed tungsten wire for a hot wire cutter, but now that I think about it (and the fact that a dull red glow would be way more than enough to cut Styrofoam) I guess many things could work, especially if a common battery charger will heat a coat hanger to yellow. That suggests that other strong (but thinner) wires might work, like stove wire, bailing wire or fencing wire. In each case the fact that they're steel would be a bonus in that you would get more resistance (desirable) per unit strength.

JohninCR · « **Reply #87 on:** 5 Mar 2007, 12:02 am »

I couldn't find a suitable wire around the house. I went around to the few hardware stores that are open on Sunday and finally found something suitable. I spent about an hour getting a rig going, and hot wire cutting is really slick. I whipped out all the circles I need in no time flat. I'm using a regulated 12 volt power supply with a dimmer switch in front of that to adjust the temp. I decided I want to go all the way simple, so I didn't crank up the sander. I'll get some heavier gauge stainless wire in the morning to do up some hot wire routing type tools, which will all but eliminate the sanding work. Change me to LazyJiffyJohn. I also want to pick up a little torch for hot bending pvc.

Bob,
Better get yourself a grinder. Fiberglass resin is some tough stuff. The smoother you can make it go on, the easier your life will be. Here I am too lazy to sand styrofoam, so I really don't envy sanding fiberglass.

Do some good with your head start, because I'll be finishing strong tomorrow after a laid back day today.

John

Bob in St. Louis · « **Reply #88 on:** 5 Mar 2007, 12:44 am »

Done for the night. Got one structure finished, ready for resin, the other has yet to be assembled.

http://home-and-garden.webshots.com/photo/2900745660085868784hOMILM
http://home-and-garden.webshots.com/photo/2760949160085868784SJuaRI
http://home-and-garden.webshots.com/photo/2592197820085868784RdLyiX

Whatcha think so far??

Bob

Bob in St. Louis · « **Reply #89 on:** 5 Mar 2007, 12:45 am »

Oh, yea....buy the way John.......One of them is playing music....

Does that mean I win? ...........

Bob

JohninCR · « **Reply #90 on:** 5 Mar 2007, 02:21 am »

Yes Bob, You win.
I don't understand something though. I see wood...no chicken wire, no putty, no fiberglass, no resin. I feel set up. They are definitely going to look cool. I like everything but the tilt...I've always felt it lowered the soundstage by sending the rear wave downward, but maybe that's my room, since I don't have carpeting. A lot have said they like tilt, so it's probably just me. The side view is kuueeelll, so I hope you're able to pull off all the curves that you want.

Bob in St. Louis · « **Reply #91 on:** 5 Mar 2007, 02:37 am »

Yea John, you've been set up. I have no resin, no wire.

Tomorrow I'll get messy aa
I agree the tilt is a bit much. The base you see is the first layer of the base. I'll add one more layer, just so it doesn't "sing". When I do that, I may tilt the entire structure up/forward just a bit.
Definite difference in the sound from my sweet spot, just from one driver. The previous mounts I had were a bit too low.
Thanks for the complement on the side view, I tried to get a little fancy. Just a little.
Now you see what I mean by the "swoopys". I tried to avoid 90 degree angles to keep it flowing.
Do you remember the ship from the movie "The Abyss"? All those flowing radii? That's what I was going for.
It'll get better when the wire mesh and fiberglass goes on. Fortunately, I have Monday off, so I'll get a lot more done.
If you never hear from me again it's because I've fumigated myself with the resin in the garage.

Take care, talk to you in the AM.

Bob

DanTheMan · « **Reply #92 on:** 5 Mar 2007, 06:49 am »

Damn Bob! Your stepping up to the plate!

I can't wait to see Johns reply.................You might be the only man in the DIY world to make him sweat. Keep up the excellent work man. When you done I've got a few projects aa

Bob in St. Louis · « **Reply #93 on:** 5 Mar 2007, 12:39 pm »

Thanks Dan!
I've been trash talkin' John a little bit, thanks for helping!!

Today is messy day...

The first thing I've got to do is build the other baffle (so the glue can be drying).
Then I'll need to go buy the wire mesh. Home Depot has some 2' X 8' metal lathe for $7 that looks pretty nice. It's the stuff you'd use if you were going to put up a stone facade.
Today will "make or break me" on using fiberglass. It's going to be chilly outside today, that's gonna suck.

But then again, it might be fun....

I'll report back and post a pic or two today assuming I'm not covered in resin. I won't step one foot in my HT room (where the PC is) if that's the case.

PICS JOHN, PICS!

Bob

JohninCR · « **Reply #94 on:** 5 Mar 2007, 03:58 pm »

Bob,

Get some disposable gloves, you'll need multiple pairs. You might check the label, I don't know if you need some minimum temp for the resin to cure.

Pics of what, some circles and rectangles? Today I should have something including pics of styrofoam tools. I just have to figure out some router type tools first.

Dan,

I'm still in the experimentation phase, so I'm not going for beauty. I just wanted to demonstrate how easy this is to use. Guys are finally starting to use their imagination, so we'll see more and more pieces of sculpture that are speakers. Once you're not restricted by a box, it becomes so much easier.

Bob in St. Louis · « **Reply #95 on:** 5 Mar 2007, 05:50 pm »

Breaktime

I've got a box of latex gloves for the upcoming mess.
(No jokes about why I have latex gloves!

Lots of mechanics use them nowdays, I bought a box from work for doing messy projects. And NO, I don't have them because I'm doing rectal examinations).

I was worried about the temperature this morning. It was 25 degrees. Now it's about 60 degrees or so.

Here's a pic of "So far", the masking tape is my cut line. The mesh was a PITA to deal with until I thought about using a pneumatic die grinder:
http://home-and-garden.webshots.com/photo/2295441930085868784MbZskE

Bob in St. Louis · « **Reply #96 on:** 5 Mar 2007, 07:24 pm »

Searching on the manufacturers website for the resin/harder mixture ratio since the directions on the can are useless.
Jesus, Man!! I buy a GALLON of resin, but the mixture instructions say 7 drops (DROPS) of hardner per TABLESPOON of resin, or 14 drops of harder per ounce of resin.
Who the hell uses a tablespoon of resin when they bought an "F"ing GALLON CONTAINER!

What's this OUNCE & TABLESPOON crap.
I buy an "F"ing GALLON and the extent of the mixture directions end at a tablespoon of resin.

W.T.F.!!!!!!!

How about a quart/XXX ratio you bastards!

Bob

goo · « **Reply #97 on:** 5 Mar 2007, 08:03 pm »

Bob, easy buddy. Think nice thoughts...ready deep breath exhale...puppies and flowers..be the water not the rock

Hope this helps
1 drop = 0.002oz
14 drops = 0.031 oz
1 Tablespoon = 0.5oz
hang in there buddy. When I work with certain formulations I have to count my drops sometimes.

q

Bob in St. Louis · « **Reply #98 on:** 5 Mar 2007, 09:30 pm »

Quote from: goo on 5 Mar 2007, 08:03 pm

Bob, easy buddy. Think nice thoughts...ready deep breath exhale...puppies and flowers..be the water not the rock

BREATH DEEP?!?!? I'll breathe deep alright. I'll be breathing deeply while I'm throwing rocks at puppies and driving over somebodies flowers in my four wheel drive truck!

Has anybody ever use fiberglass?
Holy Jesus-Mary-Mother-of-God!!!! This stuff is laughably the most user-UNfriendly product I've ever experienced. Nasty! The fiberglass "Mat" shreds itself into a fuzzy, hairy mess. Damn! The resin is so sticky, the mat adheres to YOU, not the workpiece. When you try to pull free, the mat pulls itself apart into a hairy gob of glob.
I had also bought fiberglass "cloth", so I thought I'd give that a shot.

Not much better.
Holy Hell Batman! I can't believe people use this stuff everyday. So many industries use this horrible crap, I can't believe somebody hasn't come up with something better.
I've got a hell of a mess on my hands. Before this baffle comes back in my house, one of two things is going to happen: #1 Either I'm going to get my grinder and remove all this CRAP. OR, #2 somehow I'll be able to fix this mess and turn it into an attractive speaker.

The soles of my shoes are armor plated now.

They also stuck very well to the dropcloth I layed on the garage floor as I stared in disbelieve at my new messy creation.
Then I made the mistake of walking out into my gravel driveway to take a break. Dammit. Now I've got gravel stuck to the bottom of my shoes!

I'm not sure if I wanna be pissed or start laughing.
I can't believe people use this crap. How in the hell do they do it?
This has the potential to be the most unbelievable, horrible, nasty, waste of time and money bunch of elephant snot I've ever done.
This stuff is like the hairball an old man who's been smoking for 50 years coughs up in the dumpster of a hair cutting salon.
Mix that all together and spread it over some wire mesh. See what you get.

JohninCR · « **Reply #99 on:** 5 Mar 2007, 09:47 pm »

Thanks Bob, I needed a good chuckle to start my week. I helped my buddy last year when a customer put one of his waverunners on the rocks. That was just a repair job, and building something from scratch has to be much tougher, so I feel for you. That stuff is nasty, and just when you think you got it going good, it heats up and starts burning your fingers. Just wait till you have to sand it.

BTW, I'm just idling along. Built a roundover rig and made 32ft of styrofoam roundover stock. I still haven't decided exactly how to best turn my circles into donuts. I even got to play around with the torch today, learning how to bend and stretch PVC. Did I mention that my epoxy is a 1 to 1 mix, and it's thin enough to go on with a paintbrush?

I'm just relaxing taking it slow and easy, plus I'm accomplishing a server conversion at the same time. I was up till 4am making sure that was done properly, so I have no choice but take it slow today.

Sorry to rub it in. You'll get there, and they'll be beautiful. Time for a beer break.

John