One note on silicone(the non-paintable stinky kind) is to not install your driver until it has cured or risk rotting your surround on some drivers... http://mobile.jlaudio.com/support_pages.php?page_id=164 Dave
You're right, there's no need for symmetry in chamfering out the rear of driver holes. Indeed, I use a wood rasp bit in a large rotary hand grinder since it both cuts it out fast and rough enough to theoretically bust up any reflections into much smaller (higher frequency) ones that will decay that much quicker over distance.
Ductseal is to damp the basket/motor vibrations and due to its viscosity damps HF reflections up to a point, though acoustic felt is superior for insulating the inside of the basket and/or the internal chamfer, though the latter shouldn't need it as long as the angle is at least 90 deg. from the diaphragm which generally means at least a 30-45 deg. chamfer.
A bead of rigid setting construction adhesive such as PL400 at the basket/motor junction is a good idea for cheap drivers, especially if using the screw brace or similar, but don't know if it's worthwhile with Fostex or similar better constructed units.
WRT BLH filter chamber damping, an acoustic 'blanket' on the filter chamber's roof (or bottom WRT the Frugal) and a suspended 'blanket' from its roof works well and orienting it diagonally 'kills two birds with one stone' by damping both other sets of walls, so trying different materials and/or densities by holding it in place temporarily with pushpins/whatever is what I'd do.
GM
Ductseal is to damp the basket/motor vibrations and due to its viscosity damps HF reflections up to a point, though acoustic felt is superior for insulating the inside of the basket and/or the internal chamfer, though the latter shouldn't need it as long as the angle is at least 90 deg. from the diaphragm which generally means at least a 30-45 deg. chamfer.
A bead of rigid setting construction adhesive such as PL400 at the basket/motor junction is a good idea for cheap drivers, especially if using the screw brace or similar, but don't know if it's worthwhile with Fostex or similar better constructed units.
WRT BLH filter chamber damping, an acoustic 'blanket' on the filter chamber's roof (or bottom WRT the Frugal) and a suspended 'blanket' from its roof works well and orienting it diagonally 'kills two birds with one stone' by damping both other sets of walls, so trying different materials and/or densities by holding it in place temporarily with pushpins/whatever is what I'd do.
GM
Duct seal is like oiled clay so it's mass and damping factor are high when applied to the surface of a material.
Silicone is highly elastic and good for an isolator or damper more when it's under compression, like a rubber pad. When applied to the surface of a material it's composition allows it to move with the material and not really damp the frequencies you want.
I think
Silicone is highly elastic and good for an isolator or damper more when it's under compression, like a rubber pad. When applied to the surface of a material it's composition allows it to move with the material and not really damp the frequencies you want.
I think
I'm not progressing as fast as I'd like. Finishing is a big job and since it's my first time it will end up taking much longer than the actual build. I don't like this job at all. So in that light, one more tip for the first time builder, from me to you.
Sand the inside panels that can be seen inside the horn mouth before putting the horn together.
The random orbital sander does not fit well inside this cramped space and tarnishes the adjacent surface as it bumps along, doing more damage than good. The detail sander does not fit in there at all. Since I don't like doing too much work I'm only hitting the horn mouth with 80 grit hand sanded to prevent any snags and that's about it (the rest will be done to 220 with the hand sander). The mouth will look and feel different, but I'm counting on it's recessed nature, and the fact that it's in the back, to make it "ok".
This is only practise anyway, if I get it tuned to my liking I will be making at least one more pair for myself. And then my other sister saw these and reminded me that I "forgot" to give her a wedding present too, so maybe I'll do more than 1 pair at once next time and pick the 2 nicest ones for myself.
Sand the inside panels that can be seen inside the horn mouth before putting the horn together.
The random orbital sander does not fit well inside this cramped space and tarnishes the adjacent surface as it bumps along, doing more damage than good. The detail sander does not fit in there at all. Since I don't like doing too much work I'm only hitting the horn mouth with 80 grit hand sanded to prevent any snags and that's about it (the rest will be done to 220 with the hand sander). The mouth will look and feel different, but I'm counting on it's recessed nature, and the fact that it's in the back, to make it "ok".
This is only practise anyway, if I get it tuned to my liking I will be making at least one more pair for myself. And then my other sister saw these and reminded me that I "forgot" to give her a wedding present too, so maybe I'll do more than 1 pair at once next time and pick the 2 nicest ones for myself.
just a guy said:
I'll do you one better. Do all the finishing before you assemble it. Tape the gluing surfaces first.
Another thing, and this is just my personal preference; instead of doing extensive sanding with a machine, use a cabinet scraper such as the reasonably priced stanley #80. Your lungs will appreciate it, and you'll save time. After scraping, you can lightly sand if you like.
Using a scaper plane
Be careful with thin veneers no matter what method you choose.
Hey just a guy
Before taking it all the way back to bare wood, you might want to post a description of the problem. There are some expert finishers (nope, not me) who read the forum and they may be able to suggest less drastic solutions.
In any case, don't feel too discouraged. Us woodbutchers go through this kind of thing a lot - the end result is still usually pretty pleasing.
Regards.
Aengus
Before taking it all the way back to bare wood, you might want to post a description of the problem. There are some expert finishers (nope, not me) who read the forum and they may be able to suggest less drastic solutions.
In any case, don't feel too discouraged. Us woodbutchers go through this kind of thing a lot - the end result is still usually pretty pleasing.
Regards.
Aengus
Thanks for the suggestion, but there's no hope in this situation.
I applied way too much stain thinking it would sink right into the wood. I did not realize it would sit on top like paint. Then I had to sand it and it was probably too soon, as it started to ball up and stick in hard little globs. So I started already taking it back to bare.
Not sure what I'm going to do with the back (no chance I'm hand sanding it back to bare), probably white paint. Not even sure if I want to restain the rest, maybe it's trying to tell me it wants to be gloss white instead of stained white.
Learning like this is good, if not fun. Glad this happened on a relatively small project.
I applied way too much stain thinking it would sink right into the wood. I did not realize it would sit on top like paint. Then I had to sand it and it was probably too soon, as it started to ball up and stick in hard little globs. So I started already taking it back to bare.
Not sure what I'm going to do with the back (no chance I'm hand sanding it back to bare), probably white paint. Not even sure if I want to restain the rest, maybe it's trying to tell me it wants to be gloss white instead of stained white.
Learning like this is good, if not fun. Glad this happened on a relatively small project.
Too bad, what kind of stain was it? sounds like some kind of acrylic.. Usually if you leave a stain on to long, most times you can just rub down with the compatible thinner and all is ok etc.. If worst comes to worst, you can always paint them or put on one of those built up faux finishes etc..
Dave
Dave
It's a water based white stain.
No big deal, it took 30 minutes to sand the first one down (not including the mouth) and I'll do the other one tomorrow. Hopefully I can get by with a quick sanding of the mouth and be done with that part, otherwise I'll either paint it white or hit it with turpentine and start again there too.
I didn't even think about turpentine before I started sanding away - but now that I've sanded one, I'll sand the other to avoid further mistakes.
No big deal, it took 30 minutes to sand the first one down (not including the mouth) and I'll do the other one tomorrow. Hopefully I can get by with a quick sanding of the mouth and be done with that part, otherwise I'll either paint it white or hit it with turpentine and start again there too.
I didn't even think about turpentine before I started sanding away - but now that I've sanded one, I'll sand the other to avoid further mistakes.
Yeah, if it's water-based, turpentine probably isn't going to help anyway.
I've found that with water-based stains, it's a good plan to put on "stain conditioner" (pre-stain? - can't remember exactly what it's called), which is basically clear stuff that soaks in first and stops the water-based stain from penetrating to deeply in the more absorbent areas: i.e., makes the staining more even.
The problem I ran into with the curvey harveys is that the W-B stain would only penetrate a bit into paper-backed veneer, so that even with stain conditioner the end result was somewhat patchy.
My solution? Same as with my woodworking: abandon ideas of perfection and live with, um, interesting results.
Regards.
Aengus
I've found that with water-based stains, it's a good plan to put on "stain conditioner" (pre-stain? - can't remember exactly what it's called), which is basically clear stuff that soaks in first and stops the water-based stain from penetrating to deeply in the more absorbent areas: i.e., makes the staining more even.
The problem I ran into with the curvey harveys is that the W-B stain would only penetrate a bit into paper-backed veneer, so that even with stain conditioner the end result was somewhat patchy.
My solution? Same as with my woodworking: abandon ideas of perfection and live with, um, interesting results.
Regards.
Aengus
just a guy said:
I knew it was water base.. The balling up and little globs is what gave it away. All the latex or water base acrylics will do that pretty much whenever you go nuts sanding it.. And nope, turpentine would have just got you in more of a mess for sure... The next time you get a chance on your next project,give a try with some alcohol stain, dries quick and works well. You have to work quickly and methodically with it though, methyl hydrate aka denatured alcohol is the thinner.. Dave
It's actually not that bad, I just meant to keep at it, like don't answer the phone, or stop half way through etc.. Same with any finish really, keep at it till the piece your working is complete. The alcohol stain will let you finish it up faster, as no overnight dry time needed. You can still usually save yourself if you mess up an area by rubbing it out with the alcohol, same as you would with mineral spirit stains etc..
Dave
Dave
Btw, I'm no finishing Guru, if I've given that impression.. I'm a house painter by trade ,and whenever I finish transition strips,wood railings and banisters etc ,I like to use old fashioned shellac in a cheating form of French Polishing... Here's a great intro, tons of work, but worth it if this is how far you want to take a pair of cabs.. After all that love you'll think the cabs are great even if their that 4 letter B word speaker company
http://www.milburnguitars.com/fpbannerframes.html
Less detailed http://www.am-wood.com/finishes/french.html
Dave
http://www.milburnguitars.com/fpbannerframes.html
Less detailed http://www.am-wood.com/finishes/french.html
Dave
Seal... Fill... Finish
How I finish:
Sand to 220/320
wipe down with a damp tee shirt, rase grain
Sand again...
air gun the dust off
tee shirt wipe down... dry
one coat of "Zinsser "Seal Coat 100% Wax Free" (woodworker supply) wax free won't ball up when you sand.
sand...again 220/320
air gun the dust
wipe on filler (Behlen Master pore-O-pac... woodworker supply
rub off with burlap
sand... again
dust off
tee shirt with turps wipe down
Varnish 1 part varnish 1 part real turps thinner (Behlen Rockhard table top Varnish (woodworker supply})
sand 220/320
air gun & wipe down with thinner
varnish again... full load
rub out
The Rockhard dries faster than normal varnish and is really rock hard...
Tape all your joiints and prefinish everything! In side and out. Buy great Brushes... once.
Dust will always be there... buff it out after your last coat.
And if you wanna go nuts... rubbing compound and wax... oh my
How I finish:
Sand to 220/320
wipe down with a damp tee shirt, rase grain
Sand again...
air gun the dust off
tee shirt wipe down... dry
one coat of "Zinsser "Seal Coat 100% Wax Free" (woodworker supply) wax free won't ball up when you sand.
sand...again 220/320
air gun the dust
wipe on filler (Behlen Master pore-O-pac... woodworker supply
rub off with burlap
sand... again
dust off
tee shirt with turps wipe down
Varnish 1 part varnish 1 part real turps thinner (Behlen Rockhard table top Varnish (woodworker supply})
sand 220/320
air gun & wipe down with thinner
varnish again... full load
rub out
The Rockhard dries faster than normal varnish and is really rock hard...
Tape all your joiints and prefinish everything! In side and out. Buy great Brushes... once.
Dust will always be there... buff it out after your last coat.
And if you wanna go nuts... rubbing compound and wax... oh my
So here's why I chose water base - looking at sample pics online and in store, I noticed that oil based products seem to yellow the finish. I don't mind the look of (most) wood surfaces, but I have something against yellow plywood. No idea why but I hate it. The water based stuff showed no tendancy to yellow at all, even over time (this is implied, obviously I did not stare at a sample strip for a period of many years). I wanted a white stain to reduce the contrast of the end grains (no banding tape). I've never heard of alcohol based stain, only water and wood.
And for point of contrast, here's how I finish (so far):
Sand to 220
wipe down with damp t shirt, raise grain
Sand again...
wipe off dust
apply stain, raise grain
sand again at 220
apply stain (too much), raise grain
apply a bit more stain
Sand at 220 and completely ruin the finish
continue sanding to bare wood
Pray that pre conditioner is not needed at this point (the guy in the store said I wouldn't need it if I wipe with water and sand once)
apply stain in a thin even coat with a rag, raise grain
sand to 220
continue ad nauseum, wistfully glancing at the varathane, knowing full well I may never be good enough for it
Hopefully some of these excellent tips may help me along the way. I'll find out later if I can save the mouth... I'll try hard, as I hate the thought of painting it or starting over. Through sanding the sides to bare wood, I did learn that although the stain does ball up, if you immediately wipe it away, it does not stick to the wood in big ugly thick patches. So if I can just lightly sand the mouth so it's kinda smooth, it may be passable.
And for point of contrast, here's how I finish (so far):
Sand to 220
wipe down with damp t shirt, raise grain
Sand again...
wipe off dust
apply stain, raise grain
sand again at 220
apply stain (too much), raise grain
apply a bit more stain
Sand at 220 and completely ruin the finish
continue sanding to bare wood
Pray that pre conditioner is not needed at this point (the guy in the store said I wouldn't need it if I wipe with water and sand once)
apply stain in a thin even coat with a rag, raise grain
sand to 220
continue ad nauseum, wistfully glancing at the varathane, knowing full well I may never be good enough for it
Hopefully some of these excellent tips may help me along the way. I'll find out later if I can save the mouth... I'll try hard, as I hate the thought of painting it or starting over. Through sanding the sides to bare wood, I did learn that although the stain does ball up, if you immediately wipe it away, it does not stick to the wood in big ugly thick patches. So if I can just lightly sand the mouth so it's kinda smooth, it may be passable.
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