Sunday 27 November 2016

Alpair 12P MLTLs - Day 8

Day 8 - 3 hours

Time to cut out the absorbent material and glue it in both cabinets. It's starting to feel like I'm getting somewhere now.

First, of course, temperature watch. Even I'm getting bored of this now. Anyway 9 degrees today.


Here's both cabs together after the cramps were stripped from the second.


The absorbent is old fashioned carpet underlay, roughly 10mm thick. It's not so easy to get these days, fortunately Dave the Bass had some spare he let me have. Thanks Dave :-). The top, back and one side is lined; here it's cut to size and trial fit.


I used some spray adhesive to mount the material. I was a little unsure what to use, some of the cans sounded like the bond might be a bit temporary or light, and I don't want the linings to come loose in the future. So I used a contact type adhesive, sprayed on to the cabinet and a couple of coats on the material. It comes out as a web and the fibrous nature of the lining meant it webbed up almost immediately without really making contact with the body of the material. On the other hand I found it difficult to get an even coverage on the plywood. I think it might have made quite a mess if I was trying to glue laminate, but it's good enough for this job.



Once the coats had dried so they were no longer tacky (the can says 2 to 5 minutes but it took more like 10 due to the low temperature) the pieces were placed carefully. As it's a contact adhesive it tends to grab as soon as it touches each other so steady and careful positioning was required. Then pressure was applied to ensure the two substrates made good contact. And that's it. Hopefully.


All done.


And here are the two cabinets together.


One last job for today, glue on the side of one of the cabinets. A little more time today to get a photo as there's a lot less glueing for just a side.


And here it is cramped up.



That's it for today, no more cramps.

Alpair 12P MLTLs - Day 7

Day 7 - 1 hour

Dad was round again yesterday so as well as clearing leaves from the gutters it was important I got the other cabinet glued up - it's always easier glueing with two!

First temperature watch, a little cool for glueing really, barely 5 degrees


Here's the first cab we glued last week now stripped of the cramps. Not bad, but there's a very slight bow in the front baffle. Either there's a slight bow in the bench or the composite of the ply and mdf has expanded or contracted at slightly different rates in the year it's been sat in the garage on the bench subject to the natural moisture in the air. This wouldn't have been a problem if I'd realised when glueing up, but I missed it and the side is a little "short" in centre of the baffle. It shouldn't be a problem as I think I'll have to make a cover for the baffle as the greeny grey look of the 12Ps hasn't gone down too well...


And here's the second cabinet glued up. Note the damp wood where the glue that's been squeezed out has been wiped off. Best not to get the wood unduly wet as it lifts the grain. Light sanding should fettle this.



And that's it for another day.


Sunday 20 November 2016

Alpair 12P MLTLs - Day 6

Day 6 - 1 hour

It's nearly a year since I last made any progress with these speakers. It's been a very busy time in the garden this year making trellis fences, gates, arches and a shed from scratch. But now it's winter it's audio time again!

After a long overdue tidy up in the garage I could see the bench again so I could finally start to glue up the first speaker. But first, temperature watch. It was a particularly mild and pleasant morning - 14 degrees in the still of the low slanting sun.



Not too much to talk about but here's a photo of the first gluing up. You can never have too many cramps. One side is left off as three of the internal faces are to be lined with absorbency material. Still a fair bit to do.