Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dinkyguitar on April 18, 2020, 08:42:54 am

Title: Which spray paint for OT & PT end bells?
Post by: dinkyguitar on April 18, 2020, 08:42:54 am
Hi,

I'm going to paint the end bells of my slo clone, but I'm not sure how hot the OT & PT get.

I can tell you, I'm NOT going to be driving this amp to anywhere near it's potential as far as volume.

It's a 50watt version and wanted know if I can use this paint.

https://shop.advanceautoparts.com/p/vht-paint-epoxy-satin-black-11-oz-aerosol-sp652/7141585-P?searchTerm=vht%20paint

Epoxy paint rated for 250 deg. F

I've used this paint before and really like the paint, but not on things like this.

dinky
Title: Re: Which spray paint for OT & PT end bells?
Post by: shooter on April 18, 2020, 10:21:52 am
I use gloss enamel, usually if wife's gone I'll pre-heat oven to ~100 F.  spray, shut off oven, then "bake" for ~20 min.  Repeat till caught  :icon_biggrin:
Title: Re: Which spray paint for OT & PT end bells?
Post by: 66Strat on April 18, 2020, 10:33:16 am
Get some rattle can VHT engine paint. It's readily available at most auto parts stores, rated to 550 degrees F, and lots of pretty colors.
Title: Re: Which spray paint for OT & PT end bells?
Post by: dinkyguitar on April 18, 2020, 10:46:02 am
I use gloss enamel, usually if wife's gone I'll pre-heat oven to ~100 F.  spray, shut off oven, then "bake" for ~20 min.  Repeat till caught  :icon_biggrin:

You don't know how many time I've wanted to do that.... :laugh:

But I would definitely get caught  :sad2:

I know I can use engine paint, but I haven't found "flat black" engine paint.

I found header paint in flat black....probably what I'll eventually use.

But if the bells won't reach 250 deg F...I'd like to use the epoxy paint...
Title: Re: Which spray paint for OT & PT end bells?
Post by: shooter on April 18, 2020, 11:20:42 am
Quote
VHT engine paint
:laugh:
Used plum Purple for this one  :icon_biggrin:
(bad pic angle not paint behind tubes :)
Title: Re: Which spray paint for OT & PT end bells?
Post by: bmccowan on April 18, 2020, 11:43:31 am
I doubt the temp on the bell would reach 250F. If it does, likely you have an issue. But two other high temp flat black paint options would include paint for wood stoves, and Rustoleum Barbeque Black - might be a different name now.
Title: Re: Which spray paint for OT & PT end bells?
Post by: dinkyguitar on April 18, 2020, 12:02:35 pm
I doubt the temp on the bell would reach 250F. If it does, likely you have an issue. But two other high temp flat black paint options would include paint for wood stoves, and Rustoleum Barbeque Black - might be a different name now.

True....but the reason why I choose VHT paint was to burn $5 coupon at Advance Auto before loosing it.

Once this "quarantine" is over I'll be able to go out and have more choices...

dinky
Title: Re: Which spray paint for OT & PT end bells?
Post by: PRR on April 18, 2020, 02:03:06 pm
250F is above boiling point of water.

If I spat on an amplifier transformer, and it sizzled, I'd call it "too hot!!"

I can normally touch such transformers for at least a second, which makes them far below 212F.
Title: Re: Which spray paint for OT & PT end bells?
Post by: DummyLoad on April 18, 2020, 02:25:42 pm
any old rattle can enamel will work. fast drying stuff is probably what i'd use. i like hunter green, even though that's totally irrelevant.   :icon_biggrin:   rust-o-leum or krylon are dependable brands.


--pete
Title: Re: Which spray paint for OT & PT end bells?
Post by: Bantam on April 24, 2020, 05:09:03 pm
Now I'm stuck with I spit on your Transformer but in the voice of Triumph the Wonder dog... Hahaha thanks for that hahaha
Title: Re: Which spray paint for OT & PT end bells?
Post by: nandrewjackson on April 25, 2020, 04:35:15 pm
In one of uncle Doug's YouTube videos,  he sandblast a cruddy end bell, then treats it with a chemical, something like gun bluing/browning.


I couldn't tell you which video. 


IIRC, he says many of them were done in a similar way OEM. Chemical color, not paint.
Title: Re: Which spray paint for OT & PT end bells?
Post by: PRR on April 25, 2020, 05:44:13 pm
RUSTY steel, you dose it in CocaCola or "metal prep" from the car-part store. Phosphoric Acid makes a tight oxide "conversion" which holds paint well and is less likely to rust again "soon".

A similar treatment on new/clean steel is often used on nuts/bolts and on transformers that nobody will ever see. Usually a faint yellow like old pee, not a deep black or blue like for-show transformers.