BC 8" cab

[tauzero]

Battens already cut to length and drilled.

 

My circular saw proved capable of cutting a triple layer sandwich (once I set the cut height right). I used a different cutting pattern as I was cutting a maximum of 610mm - first a cut across at 300mm, then a second and third at 376mm. After that, I stacked the three pieces and cut at 276mm twice, so a total of five cuts.

 

First, I made the sled - I'd glued and screwed a length of batten across the panel, and just cut across using that as a guide.

 

 

Then I clamped up for the first cut, and found that when I'd just nipped up the fixing bolt for the blade that my definition of nipped up and the instructions definition of nipped up are different. Once rectified, off we went. The first cut is the shallowest.

 

 

After that first cut, I was able to use the piece I'd just cut off to rest the other side of the circular saw base on.

 

 

Another cut the same and then I stacked the wood.

 

 

And at last got to the final cut.

 

 

I still have to cut out holes in the front and rear.

[nekomatic]

Game on! Looking forward to seeing more of these nifty little cabs coming to life. 

[SpondonBassed]

1 hour ago, tauzero said:

I still have to cut out holes in the front and rear.

 

Have you decided how you want to do this yet?  I have some decent sized hole cutting tools if you want to visit and use them.

[tauzero]

6 hours ago, SpondonBassed said:

 

Have you decided how you want to do this yet?  I have some decent sized hole cutting tools if you want to visit and use them.

 

Porthole is no problem (holesaw), also the control plate (jigsaw). I'm weighing up how best to do the speaker cut out, I also have a palm router (and a plunge router although I'm not sure about the chuck on it).

[tauzero]

Connector plate hole cut out - I cut it a bit undersize then chamfered the edge, and I may well do the same thing for the speaker hole. Port hole also cut. Router jig ordered to cut circular hole. Battens applied to sides.

 

Due to a dose of flu, I've called a short halt because bouts of dizziness and power tools don't mix.

 

I have a feeling that I may need to sand down the sides of the front and rear panels as they're a tiny bit short and a tiny bit fat.

[SpondonBassed]

7 minutes ago, tauzero said:

a tiny bit short and a tiny bit fat.

 

Yet sporting eight inches...!

 

GWS

[tauzero]

The sides all battened up.

 

 

Yes, that batten is a bit long - it's now been sanded down.

 

 

 

I still have to do a tiny bit of tidying to the chamfering as the connector plate isn't absolutely flush - only about 1mm off.

[rwillett]

Does anybody have any experience of Granotone speaker paint? 

 

I'm looking at options for finishing the cab. 

 

So far I could paint it in a similar way to @Pea Turgh or I could use a more traditional textured speaker paint or I could do something off the wall like Rustins textured step paint in red. 

 

I rather fancied red speakers and did look at Tuff Cab but they have none in stock of any colour. I've been told Tuff Cab is really Aldcrofts in Bolton but a number of people elsewhere have stated that Aldcrofts are very difficult to deal with. I'll drop them an email and see what they say. I can drive to Bolton quite easily if I choose to work in Manchester for the day. 

 

Most of the black speaker paint appears to be expensive and come in quarts or fathoms or gallons or something. The Warnex stuff appears to be in German and even though I lived in Hamburg for a while my German is crap. 

 

There's doesn't appear to be a lot of choice here so wondered if anybody had tried Granotone or have other suggestions for a tough finish. It looks like there are more open mics and other sessions comjng up so I think I need a tough finish on these cabs. 

 

Thoughts welcomed. 

 

Rob

[SpondonBassed]

Hammerite comes in a variety of colours both smooth or hammered finish.  Although it's expensive, it is quite tough as long as you have a compatible primer to support it.

 

It's impressive when sunlight hits it so I'd imagine stage lighting would have a similar result.

 

It is excellent for painting directly onto metal that has had the loose rust removed with a wire brush.  It works well with plastics when you use the appropriate primer.  I'd happily use it on a cab.  It does take a while to fully cure however.  You will need good ventilation too.  It stinks for the first few days.

 

 

 

 

 

 

 

Edited Friday at 12:02 by SpondonBassed

[tauzero]

4 hours ago, rwillett said:

There's doesn't appear to be a lot of choice here so wondered if anybody had tried Granotone or have other suggestions for a tough finish. It looks like there are more open mics and other sessions comjng up so I think I need a tough finish on these cabs. 

 

Just wondering the same myself. There appear to be Tuff Cab (available in white or yellow only, nothing else out there), Granotone (5kg for £60, 800g for £25), and DuraTex (£100 for 32ml - that's just over six teaspoons, although it seems it's really a pint which would be more like 550ml).

 

https://www.amazon.co.uk/DuraTex®-Furniture-Application-Water-Based-Professional/dp/B0CTS54R8X?th=1

 

Hammerite?

[tauzero]

4 minutes ago, SpondonBassed said:

Hammerite comes in a variety of colours both smooth or hammered finish.  Although it's expensive, it is quite tough as long as you have a compatible primer to support it.

 

It's impressive when sunlight hits it so I'd imagine stage lighting would have a similar result.

 

It is excellent for painting directly onto metal that has had the loose rust removed with a wire brush.  It works well with plastics when you use the appropriate primer.  I'd happily use it on a cab.  It does take a while to fully cure however.  You will need good ventilation too.  It stinks for the first few days.

 

 

 

 

 

 

 

 

I see we had the same thought.

[rwillett]

We've all had the same thoughts and come to similar conclusions which I find highly amusing.

 

One other thing to add, the Aldcrofts paint (which I think is Tuff Cab) only has an unopened shelf life of six months. I worked out that doing two 8" cabs with three coats uses approx 1Kg, and the chances of me using it again is low, so its very expensive to paint two cabs. If I lived closer to people I'd happily pass tins along but unlikely to happen.

 

I like the look of the Hammered Hammerite but thats not cheap either at circa £10 / 250ml.

 

There is this site that tests how it works on different woods and it comes through with flying colours. They don't mention the primer they use though.

 

https://patientgardener.co.uk/can-you-paint-hammerite-on-wood/

 

I have seen a suggestion of using an oil based primer for undercoat https://www.vintage-radio.net/forum/showthread.php?t=93459

 

I think I'll head to Settle later and see what they have in my local DIY store. Hammered red might be interesting and if nothing more, I'll use the can on something.

Rob

[basstone]

24 minutes ago, rwillett said:

We've all had the same thoughts and come to similar conclusions which I find highly amusing.

 

One other thing to add, the Aldcrofts paint (which I think is Tuff Cab) only has an unopened shelf life of six months. I worked out that doing two 8" cabs with three coats uses approx 1Kg, and the chances of me using it again is low, so its very expensive to paint two cabs. If I lived closer to people I'd happily pass tins along but unlikely to happen.

 

I like the look of the Hammered Hammerite but thats not cheap either at circa £10 / 250ml.

 

There is this site that tests how it works on different woods and it comes through with flying colours. They don't mention the primer they use though.

 

https://patientgardener.co.uk/can-you-paint-hammerite-on-wood/

 

I have seen a suggestion of using an oil based primer for undercoat https://www.vintage-radio.net/forum/showthread.php?t=93459

 

I think I'll head to Settle later and see what they have in my local DIY store. Hammered red might be interesting and if nothing more, I'll use the can on something.

Rob

I’ve had a large tin of tuff cab ( black satin) open for about 5 years and have used it on 2 speaker cabs, several rack cases and 2 large stage risers and it’s still going. I just give it a stir to even out the consistency before use. It’s the best durable professional finish I’ve ever achieved on my projects. It does seem hard to get at the moment though. 

[rwillett]

I've contacted Aldcrofts. I'm quite neat Bolton so let's see what they say. I'll also look at the Hammerite stuff 

[tauzero]

1 hour ago, basstone said:

I’ve had a large tin of tuff cab ( black satin) open for about 5 years and have used it on 2 speaker cabs, several rack cases and 2 large stage risers and it’s still going. I just give it a stir to even out the consistency before use. It’s the best durable professional finish I’ve ever achieved on my projects. It does seem hard to get at the moment though. 

 

Tuff Cab is Blue Aran's own brand and they're not stocking it, so it looks like one ingredient must be unobtanium.

 

Edit: or Aldcrofts have stopped supplying them. At £72.50 for 5kg and no smaller quantity available, Aldcrofts aren't cheap though.

 

https://www.aldcrofts.com/product-page/c64-31-matt-black-speaker-paint

Edited Friday at 15:41 by tauzero

[rwillett]

Got a small tin of Hammerite Hammered Red. Need to find some oil based primer and will try tomorrow. Too cold now. 

[tauzero]

Just found https://en.toutlehautparleur.com/loudspeaker-components/paint/warnex-1kg-professional-paint-pot-black-textured-special-for-enclosures-honeycomb-roller-application.html - 1kg tin of Warnex for 25EU plus whatever getting it across the channel will cost. Black and grey available. Should cover up to 3 cabs.

[rwillett]

What were the shipping costs for this from France?

[Stub Mandrel]

Could you use a textured paint then prime and give it a top coat in a durable red?

[stevie]

Blue Aran hasn't had any black Tuffcab for months. Your best bet is to get a litre tin of Armacab from Penn Elcom. It's very similar to Tuffcab but thicker in consistency and with a higher pigment content. It'll cost £27 delivered. To get a decent finish, you'll need the foam rollers from Blue Aran. Unfortunately, they're out of stock of those as well but they're due in mid-December according to the website.  

 

In current weather conditions, it'll take some time to dry. So, leave each coat to dry overnight - and don't allow the paint to freeze, as it will then be useless.

[nekomatic]

I have several of the rollers spare and would be happy to post a couple to any cab constructor. You’d need your own handle but I think that’s a standard size. 

[Stub Mandrel]

They are a standard diy item for wall painting. 

[rwillett]

1 hour ago, stevie said:

Blue Aran hasn't had any black Tuffcab for months. Your best bet is to get a litre tin of Armacab from Penn Elcom. It's very similar to Tuffcab but thicker in consistency and with a higher pigment content. It'll cost £27 delivered. To get a decent finish, you'll need the foam rollers from Blue Aran. Unfortunately, they're out of stock of those as well but they're due in mid-December according to the website.  

 

In current weather conditions, it'll take some time to dry. So, leave each coat to dry overnight - and don't allow the paint to freeze, as it will then be useless.

How did I miss that from Penn Elcom? That's sensibly priced as well. Here's the web page

 

https://www.penn-elcom.com/catalogsearch/result/?q=Armacab

 

Does this mean that if I brought white I could tint it red  ?

 

Rob

[rwillett]

Ordered a 1L tin from Penn Elcom. Will look at what rollers are best for pattern so any suggestions welcomed.

 

Finally had a day of clear weather so managed to get outside to cut things and create quite a lot of sawdust.

 

The speaker cab is almost there, port hole made and the printed version fits in nicely. The speaker hole looks great (even if I do say so myself), the router and the home made adapter works a treat.  The marks from the circular saw will disappear as I'll gently sand and it's coming to be covered with black Armacab.

 

 

I also cut the hole for the spray cabinet extractor fan and the power switch. Not wired up yet but that's not a big deal. 

 

 

Got 5m of extractor hose that will go on the extractor fan so it takes a load of the fumes and spray away.

 

Todays job is doing the rear connector panel and probably soldering wires in. It's also raining.

 

A few questions:

1. I'm unsure how to mount the rear connector panel. Should I just put foam tape on the inside and squash it down to seal it and that's the gasket to reduce leaks. If so I'd probably need to recess the panel so it doesn't stick out too much. I feel I could do that now I've had some practise with the router. I could just put sealant on the underside and squash that. Not sure of the best way.
2. Should I use screws or bolts for the rear panel? I can put an M3 bolt through and a lock nut on the other side. Not sure which is best. I have both so it's not an issue
3. Should the loudspeaker be bolted in or screwed in? It appears to have quite a dense foam on the front and rear of the Fane speaker.  So assuming that I don't need any more foam around that?
4. I'm intending to solder the internal wires to the speaker. I've seen comments on using spades but can't see any issues with solder myself.

The reason I'm asking these is that I can't do bolts on both systems as I lose access as the front and rear panels go on. So am assuming that screws are probably the way to go, possibly with some sealant to help lock them in? 

 

Thanks

 

Rob