12" Cab Diary Continued

[stevie]

Finally.... grilles. These were always a bit of a problem. But now we have several options.

First, I bought a sheet of expanded metal and cut my own to size. It took a lot of experimentation and some hardware purchases to figure out how to do it properly. That's the one that funkle has, and you'll no doubt see it very shortly in his build thread. It's primed lightly with zinc primer and painted with Plastikote. I have enough of the expanded metal to make a few more. So if you're interested in one of these, let me know and I can include one with your kit.

Luke brought the other options to my attention. There is an Ebay seller who will cut punched metal to size and send it through the post. He offers mild steel and aluminium. I decided to get an aluminium one for £15. Now, the problem with aluminium is that it won't take normal paint directly; you have to use an etch primer. That adds about £10 to the cost. So you're looking at around £30 for an aluminium grille. For some, the weight saving will be worth it. Others might like to go for the mild steel alternative.

The mild steel one costs £8.95, and you can paint it directly with Plastikote or similar spray paint. The German discounters regularly sell an equivalent for around £2.99 a can, and it's not bad. These paints do a fairly good imitation of powder coating and are quite tough in practice.

Anyway, here's a photo of the aluminium grille on my cab. The white coating is a protective film which I've not yet removed as I've not got around to painting it yet. The photo of the grey paint on the wood is probably the best one I took. That's more or less how it actually looks.

Edited September 6, 2019 by stevie

[Pea Turgh]

That will look really cool with the orange bits in the badges.

[Chienmortbb]

I like the look of that and I don’t want the weight of a steel grille. It looks similar to Torque grilles if my memory serves me correctly. 

[LukeFRC]

That looks well good! Almost tempted to go for the aluminium grill

[stevie]

1 hour ago, Chienmortbb said:

I like the look of that and I don’t want the weight of a steel grille.

The expanded metal grille isn't that heavy, although obviously heavier than the aluminium one. I expect the punched mild steel one will be the heaviest, although I haven't actually weighed any of them.

[stevie]

The difference in price between the steel and aluminium grille isn't that great - it's the cost of the primer that makes the aluminium one so much more expensive.

However, Luke has just pm'd me with the idea of keeping the aluminium look (he keeps sending me these neat ideas). So if we can find a clearcoat to spray over the aluminium to stop it tarnishing, that could be a solution. Depends on how an aluminium grille looks, of course.

[funkle]

Ooh that grill is tempting. However I already own mine, lol, so I need to use that first. 

[stevie]

I'm leaving my cab to harden up a bit overnight. It's dry now but the paint still seems a bit soft. I'm not sure it's a great idea to load it up just after painting it.

[RichardH]

I was going to say - aluminium grille with the grey cab would look great. That finish you've got looks really nice - very "pro PA cab".

[stevie]

I agree, it could be a nice look. I'll be hammering Google this weekend to find some kind of spray coating that works. Then we can all see how it looks.

[tauzero]

What about having it powder coated?

 

[stevie]

Yes, that's definitely an option. I have a specialist aluminium powder coater not too far away from where I live and I'm planning to ask him for a quote - although I suspect a one-off could be expensive.

That doesn't really help anyone else though, unless they can find a local powder coater who does aluminium (I believe aluminium uses a different powder coating process to normal steel). So I'm still going to look for a spray can that would do the job. It wouldn't need a thick coating - it's just to stop the aluminium tarnishing with age.

[Stub Mandrel]

Get it anodised. 🙂

 

[MichaelDean]

6 hours ago, stevie said:

Yes, that's definitely an option. I have a specialist aluminium powder coater not too far away from where I live and I'm planning to ask him for a quote - although I suspect a one-off could be expensive.

That doesn't really help anyone else though, unless they can find a local powder coater who does aluminium (I believe aluminium uses a different powder coating process to normal steel). So I'm still going to look for a spray can that would do the job. It wouldn't need a thick coating - it's just to stop the aluminium tarnishing with age.

You might want to look at Spray.Bike. It's powder coat in a can and adheres to most metals. Not cheap, but after doing a bike frame myself, I think you'd get quite a few grills with a can. 

Edited September 7, 2019 by MichaelDean

[LukeFRC]

On 07/09/2019 at 18:36, MichaelDean said:

You might want to look at Spray.Bike. It's powder coat in a can and adheres to most metals. Not cheap, but after doing a bike frame myself, I think you'd get quite a few grills with a can. 

Did you end up doing a top coat on top? 

Looks interesting!

[MichaelDean]

34 minutes ago, LukeFRC said:

Did you end up doing a top coat on top? 

Looks interesting!

Yes, I used their one. I should have ordered two cans of the clear coat though - it doesn't quite go as far if you want a gloss finish. My bike is a bit shiny in some places, but not all... 

[stevie]

Anodising is definitely a professional job, unless you're happy pouring sulphuric acid in your bath and putting an electric current through it. The cost could be acceptable even for small quantities, but for a one-off you'd pay a minimum charge, which as far as I can tell, would be £50+.

The same goes for powder coating. It's cheaper than anodising but I'd estimate at least £20 for a single speaker grille, unless you can persuade a friendly powder coater to stick a speaker grille in with something else they're coating at the same time.

Spray Bike looks very interesting, but if you read the small print they say it needs a primer coat.

So, I can't see any way round buying a can of etch primer and painting the aluminium grille yourself. I  tried painting a corner of my grille with some normal spray paint, but it comes off easily.

I'm going to get the weights of each of these grilles and will post the info later this week so that builders can choose the best option for them.

There's also the option of a fabric grill, of course, with Fender or Marshall cloth, and if you decide to do that, be sure to post the info on the thread.

Edited September 9, 2019 by stevie

[Stub Mandrel]

1 hour ago, stevie said:

Anodising is definitely a professional job, unless you're happy pouring sulphuric acid in your bath and putting an electric current through it. The cost could be acceptable even for small quantities, but for a one-off you'd pay a minimum charge, which as far as I can tell, would be £50+.

Anodising needs care, but as long as you have a large enough plastic tray your could anodise it yourself. I do anodising in my workshop.

https://www.gaterosplating.co.uk/anodising-main

[RichardH]

I made some cases for my home built hi fi amps a few years ago, made from aluminium sheet. I used an etching primer from Halfords to spray it - followed by a satin black spray. It worked really well, and has been solid over the last few years - but it obviously gets a lot less in the way of knocks than a bass cab.

[LukeFRC]

3 hours ago, stevie said:

There's also the option of a fabric grill, of course, with Fender or Marshall cloth, and if you decide to do that, be sure to post the info on the thread.

I'm planning a fabric grill.

The main consideration you have with fabric is how open it is - Unlike Barefaced with their slot port or equivalent, the port sits behind the grill - and is sized to move a fair amount of air.

I've ended up buying some beige insect mesh which is 54% or so open and will let me get it taught. The downside is that it may not be opaque enough to look good! 

The aluminium grill Stevie has looks the dogs do-dahs and it would be only a little more ££ to paint it... the spray bike needs a top coat but does come in nice colours!

Edited September 9, 2019 by LukeFRC

[stevie]

Quick update. I've fitted the corners, feet and handle - with sticker - to the cab but can't do much more until I have the etch primer to paint the aluminium grille. It's on order and should be with me this week. I'll cut and paint another expanded metal grille as soon as I can so that we can compare the two options visually.

The dark grey paint looks stunning against the black fittings and the black and red badges - so I've decided to paint the aluminium grille satin black.

I've notified the CNC company of the minor changes needed and confirmed the order for 10 kits. They have said two to three weeks, which will give me time to build the crossovers.

Edited September 11, 2019 by stevie

[converse320]

When do you need payment Stevie?

[stevie]

I'll need payment when I have to fork out for the cabinets and the compression drivers - that's too much for me to fund on my own. However, I don't want to sit on anyone's money unnecessarily. So I'll let you know in good time.

[stewblack]

1 hour ago, stevie said:

I'll need payment when I have to fork out for the cabinets and the compression drivers - that's too much for me to fund on my own. However, I don't want to sit on anyone's money unnecessarily. So I'll let you know in good time.

Or sooner - don't give me opportunity to spend it!

[stevie]

I hope you haven't spent your money, @stewblack because things are progressing more quickly than I'd expected. The cab kits are likely to be here early next week - probably before everything else is ready. If you can collect, you can probably have your kit next week if you don't mind waiting for the other bits and pieces.