The Unofficial Mamod and Other Steam Forum

mogogear · Posted: Sun Apr 20, 2008 3:06 pm Post subject:

Pete - the Gun Gum looks to be great stuff-- the peened rivets worked out spot on too!! Better weather for your painting soon!!

I have s firebox to make soon as well..

Is there a brand or name on your gun gum?
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regards,

Mo

This week I are His Most Noble Lord Mo, the Apocalyptic of Old Tonbridge Wafers

RocDoc · Posted: Sun Apr 20, 2008 3:50 pm Post subject:

Hi Mo,

The Gun Gum is made by Holts. You should be able to get something similar it in any auto repair center. It's a thick paste for repairing holes in exhaust systems. I also used some fine aluminium mesh for 'reinforcement' over the hole otherwise the gun gum wouldn't have had anything to stick to.

I haven't tested the repair yet. Just hope it holds together under the combined attack of heat, steam and meths.

Pete

mogogear · Posted: Sun Apr 20, 2008 4:31 pm Post subject:

Thanks Pete- keep me informed on if your aesthetic solution is viable under "fire"!!
_________________
regards,

Mo

This week I are His Most Noble Lord Mo, the Apocalyptic of Old Tonbridge Wafers

RocDoc · Posted: Mon May 05, 2008 9:12 pm Post subject:

After a short wait, I'm 'pleased' to say Mo that the great Gun Gum experiment to patch the firebox has failed with a capital F!

I applied the Gun Gum as instructed, made it nice and smooth. Applied several layers of heat resistant paint (Plasti-Kote BBQ paint) ... all looking really nice. Then I baked the firebox in a slow oven starting at 70C for 45 minutes. As the temperature went up the paint covering the Gun Gum started to blister big time ... the rest of the firebox was perfect, no blisters, nothing. I didn't notice it but I reckon the paint was blistering at 70C.

I did a little test. I turned my blow torch on to the repair ... sure enough, the remaining paint blistered and came away. The Gun Gum itself started to deform and blister.

Looks like Gun Gum ain't that clever for repairing fireboxes. It doesn't sand smooth and doesn't take paint (at least the paint that I was using).

So folks, I'm back to the very beginning again. There's a hole in firebox dear forum, dear forum ...

Any suggestions on what to do next?

Pete

johnreid · Posted: Mon May 05, 2008 9:17 pm Post subject:

I would suggest using a piece of sheet metal. Either cover the whole end of the Firebox, or try to patch the hole with it, I would try to make a piece to cover the entire end of the Firebox if it was me trying to do it..
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Your life is an occasion...Rise to it

RocDoc · Posted: Mon May 05, 2008 9:20 pm Post subject:

johnreid · Posted: Mon May 05, 2008 9:26 pm Post subject:

Although it might not be an invisible patch, personally I would Rivet, if you can Silver Solder that might be better, but I fear that soft solder would melt.
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Your life is an occasion...Rise to it

Les · Posted: Mon May 05, 2008 9:29 pm Post subject:

Just sent you a PM.
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Les - Old age isn't so bad when you consider the alternatives.

www.freewebs.com/lesmarsh

MooseMan · Posted: Mon May 05, 2008 10:21 pm Post subject:

I think brazing a piece on, or possible a replacement firebox would be the way forward.

Pity about the gun gum though.
_________________
Stands the glass half empty,
Or stands the glass half full?
Blast your Buddhist mantra, man,
I'll take another pull.

RocDoc · Posted: Mon May 05, 2008 10:25 pm Post subject:

MooseMan · Posted: Mon May 05, 2008 10:35 pm Post subject:

Hurray! Definitely the best solution in the long run. Three cheers for Les!

BTW, just packed up your 122.
_________________
Stands the glass half empty,
Or stands the glass half full?
Blast your Buddhist mantra, man,
I'll take another pull.

RocDoc · Posted: Mon May 05, 2008 10:39 pm Post subject:

Thanks mate. That will be something to look forward to when at work.

Pete

Mamodman123 · Posted: Mon May 05, 2008 11:43 pm Post subject:

Exhausts get hot......but obviously not that hot. At least its been tried and tested now

Hope you can get the replacement

_________________
Solid Fuel tablets explode

You could get a nice flatbase for that

www.mamodsteam.tk

johnreid · Posted: Mon May 05, 2008 11:45 pm Post subject:

Isnt this a great place?
Three Cheer for Les.
_________________
Your life is an occasion...Rise to it

RocDoc · Posted: Tue May 06, 2008 8:37 am Post subject:

Indeed it is ... a great place