Vented Tritrix Curved Build - Page 2

Guess i'll cross Lauan off the list then. Thanks for the advice.

Can i get some opinions on using different veneer on the baffle and the rest of the box?

I was considering that for this box since i have an assortment with a lot of different stuff, not a ton of any one species. After lining up a few different combinations on my first prepped cabinet i'm thinking maybe it's not a great idea.

Things have not gone all that great in the glue up process. My jigs are just not sufficient, as i mentioned before. They need more than 3 braces and must be oversized to hang over the end of the workpiece and apply pressure all the way up to the end of the join.

The cabinets are not coming out stellar, but i moved on to trimming the overhang last night. I think this was the first time i ever used the angle feature of a jigsaw base. I drew a line leaving maybe 1/8"-1/4" of overhang to avoid accidentally clipping the face of the cabinet with the jigsaw blade, then dialed in the correct angle on the base of the jigsaw, and cut away the overhang.

I only had short-side overhang on one side of one cabinet because i had cut the other cabinet's panels exactly to size before glueing. Unsure which approach i prefer. Oversizing and trimming is more failsafe but more work. I couldn't reach the long-side overhang with my tablesaw blade with the cabinet in my jig, but the short side did reach if i didn't use the jig. I ended up free-handing the trim with the tablesaw. One of stupidest things i've ever done. Don't do it. I won't be trying that again.

I've found one of the poor quality items from Harbor Freight is their belt-sanding belts. I rarely use my belt sander (also from HF) but when i have, the HF sanding belts ALWAYS break at the seam. I went through 2 packages of them before giving up. This past week i picked up some quality belts and they make a HUGE difference. I went with a super aggressive grit and you really need to be careful. 36grit on a belt takes off a LOT of material in a hurry.

I cleaned up with 80grit on my random orbital (probably my favorite tool in the whole garage).

Last week I did some veneer work. While trimming the edges with my router, i must have leaned it a funny way and it ate through the veneer near an edge really bad. I did the same thing on my last project in a few spots. i think i need a dedicated tiny laminate-trimmer... i never seem to hold the big router stable and plumb.

It was so bad that i thought i would try to patch it. i don't think this is an orthodox patch procedure but i gave it a shot. I cut out a piece of veneer that looked like it had a similar grain pattern and glued it over the exposed MDF with my trusty hide glue. I didn't have any more sheets of the same veneer so i couldn't use an exact excerpt from another sheet.

After the glue dried, i sanded it smooth. After sanding about 1/2 of the patch down to smoothly meet the existing veneer i was really impressed. Came out really good. My fortunes were not quite that good with the other 1/2 of the patch. I don't think I pushed out the glue well enough on the other side so the veneer started to flake when i sanded it super thin (usually the hide glue holds it really well even when sanding down to flush). Going further and further in search of a clean 'vanishing' glue line, i ended up sanding through the patch. Oh, the irony.

In the end, it looks like crap. probably no better than the original error. But i believe it *could* come out good if i had been more careful with the glue and the sanding.

Trimming the edges of veneer overhang on curved builds can be a pain. This time i tried using a dremmel with cut-off discs. Worked pretty well. The last 1/4" or 1/8" that remains gets taken off with a random orbital held with pad travelling parallel to the edge... the perpendicular stroke of the d/a had given me chipping problems in the past.

I also cleaned up the port on the back and gave it a roundover. Still unsure how i'll handle the roundover... perhaps white paint. or perhaps i'll just leave it as-is and assume nobody will ever look at the back of the cabinets

I had some Jasper-Jig woes when trying to cut the speaker holes. There are a few radius settings where the holes in teh jig are blocked by the router base. In those cases, the pivot only sits maybe 1/8" into the jig itself. I got unlucky and the pivot worked its way down into the hole in the workpiece while i was cutting the countersink passes. Luckily the router pushed inward and took a divot out of the useless negative space and not outward, which would have ruined the baffle. Guess i have to get lucky sometimes.

I used a utility knife to slice a few chunks away from around the burried pivot and grabbed it with some needle-nose.

Oh - and i ran some test cuts on scrap before hitting the baffle. I recall one kit i made the measurements i had printed out were slightly off, so i always try a practice run now to make sure things fit before i go ruining my cabinets. I figured it unlkely that the Tritrix kit would have the wrong figures in the diagrams but it doesn't hurt to be sure.

I sanded all the crud off the cabinets and they're just about ready for finishing. I recently remembered that i bought some 100% tung-oil online a while ago after getting duped at Home Depot and buying some 'fake' tung oil. That looks like the way i'm going with the finishing. Maybe a few coats of tung oil and a few coats of shellac. I think that's safe but welcome comments. I think the shellac is a harder top-coat than just the tung oil? I need to pick up some turpentine to cut the first coat of the oil. Hopefully get that underway this week sometime.

Went to town with the tung oil this afternoon. I picked up some turpentine to thin the oil for the first coat as i'd read about 1:1 oil to thinner.

Another interesting comment on the tung oil, the air must be displaced form the container for storage. The manufacturer recommends squeezing out the air before capping the remaining oil or filling the empty space with marbles. Didn't have any marbles on hand so i just squeezed out the air.

I rubbed on the oil with cotton rags, waited about 30 mins, then wiped off the excess. For some reason my expectations for the oil were very high. I can't account for it. I'm not overly impressed so far. Might wipe on a second coat of the thinned solution tonight and then start with coats of the straight oil tomorrow. Hope the color gets deeper with more coats.

Thanks for the suggestion Tim.

I'm wondering if i can go super cheap with the trim router. I don't need a precision plunge gague or anything - just something easy to handle that will spin a flush-trim bit. What do you think?

http://www.harborfreight.com/1-4-qua...ter-44914.html

Tim - that porter cable trimmer looks nice. I'll have to weigh my options when i start another build. If I score a 20% coupon, that harbor freight trimmer will be so cheap I might be *forced* to pick one up and give it a try :-)


Chris - glad I'm not the only one thinking that way. To my amazement the round over exposed Mdf is actually looking kind of nice with the tung oil on it.. It darkened up a bit. Not sure how it will look when fully cured, but as of now I'm thinking it won't get any special attention past the oil I'm applying to the entire box


Just found this stuff while looking up info on sanding between coats of oil. A nice dark hue would have probably been right up my alley. Maybe nex time

http://www.realmilkpaint.com/dark_oil.html

good grief - this tung oil takes a long time to dry.

I read so many different opinions on how to apply it. i ended up doing 2 coats with it cut 1:1 with Turpentine, then i think 3 coats of the oil alone. I generally waited 12 to 24 hours between coats. It wasn't really fully dry between, but those were the guidelines i was going by.

I only sanded once - between coats 2 and 3 of the pure oil applications. At that point the previous coat was pretty dry ( i gave it 2 or 3 days). I dry sanded with a 500 grit abralon pad by hand. Afterwards i tried another application approach i had read about. I used the sanding pad as the application pad for the 3rd coat of oil.

Looks pretty good but taking a serious amount of time to dry. It's been 3 days and it still feels oily. I've wiped the surfaces about once a day for the past few days, but still not fully dry. Think i'm going to call the oil work done. Once it seems dry i'll put in the crossovers and drivers and give it a listen. I plan on hitting it with a topcoat of shellac, but i hear its best to give the oil up to 30days to fully cure first

Did the final assembly today. I had lined the back and side walls with foam a few days back. Have to look around for more foam to do the top. I velcro'd the crossovers to the bottom today - not sure if there's much room put any damping around them.

Everything fit pretty well except that the countersink for the mids in one cabinet could have been a tiny bit deeper.

I'm fairly well satisfied with the look of the final product. Has my typical DIY woodworking mistakes, but nothing major like the giant wart on my last sub build

The tung oil darkened up over the past week. Looks alright. Smells a lot better than some other finishes and isn't toxic. That gets high marks in my book since my garage is the workshop. Still feels a little greasy so i imagine it's not totally done drying. In a month or so i'll revisit the look and feel of the finish and consider another topcoat (probably shellac as i mentioned previously).

Not sure when i'll have a chance to hook these up and listen/measure. Got a few other things going on. Glad to see these two assembled tho. It's a nice looking design. I like the look of that dome tweeter - though i'm terrified for it's safety. Might have been a good build to try my first magnetic grill. Oh well.

Thanks PI. Aside from some sand-through and a few wonky veneer seams, i think the build went pretty well. I like laminating MDF with jigs for bending the curves over kerf cutting approach. Definitely need better/stronger jigs next time though.

Haven't had a chance to listen to them yet but i tried to run some quick measurements this morning to make sure all the wiring was alright. I was 0 for 2 out of the gate. lol

First cabinet, no sound

Second cabinet, see curve.

No time to really troubleshoot this morning, but i opened up the first cabinet because i had a feeling i knew the problem. I forgot to crimp down the spade connectors going to the main terminals - they were very loose and must have come apart when i was connecting the rest of the wiring. After that fix, it measured significantly better than the attached curve from the second cabinet. Because i was in a rush i accidentally cleared the curve from Omnimic before saving it out to a file and had alraedy cleaned up the measuring equipment... so no curve for that guy.

Kind of curious about the second curve. My first thought was tweeter out of phase because of the big dip near the crossover frequeny. But there's also a cliff at 5.5k. Must have wired the crossover wrong. Maybe i'll have a look tonight. These measurements had the back of the enclosure about 5" from the wall, which i expect hurts the low end for a rear- ported design? More measurement variations to come when i have more time.

Fixed the problem on the second cabinet - it was a bad solder joint on the crossover. I'm surprised anything was coming out of the tweeter at all. Very odd.

I did some measurements but later realized my wife bumped up the bass boost on the receiver. Can't remeasure at the moment. There are a bunch of hills and valleys under 100hz. I think some is from the bass boost and some is from the walls. I'd like to measure outside but i don't think it's ever quiet enough in my area.

DId some listening. They sound very good to me. Vocals in some Beatles tracks were sort of creepy - very natural sounding. I don't often do critical listening. It was kind of nice.

My first impression is that they sound better than my Zaph ZA3.5 towers, but I can't remember the last time i listened to music on those. I''d like to try to setup a side-by-side test.

Funny thing is, as someone pointed out in another thread, with all these DIY projects, i don't really know what to do with all my speakers now

Wanted to use them downstairs but one of our pets chewed the surround on the last pair of open-front speakers i left in that room Nothing without a grill goes down there from now on.