Dum Dum. Where to buy?

Alan Surrey

Alan Surrey

Member
Messages
993
Where can I buy the substance I know as Dum Dum?
The tin I have had for decades has dried up and right now, for the first time in years, I need some.
It is automotive putty. A black substance that can be worked in the hand like plasticine or blu-tac but more flowing than either, more like glazier's putty in that respect. It seeks - flows into the tiniest spaces - and then it stays there, preventing moisture from passing through the space and unlike glazier's putty, it never really sets solid. Once you get it on your hands you probably need Swarfega or maybe an amputation to get it off. It is generally used to make a water tight gasket. If you were to insert a screw where it could be rained on (and this is what I am doing with my car's scuttle) you would want to make a little gasket of Dum Dum and place it under the washer. As you tighten the screw it compresses the Dum Dum gasket under the washer and the Dum Dum flows one way into the threads of the screw - no water can get through that way now - and the other way, it becomes compressed out to the edge of the washer so no water can get through underneath the washer either: practically a perfect seal! You can put a blob of it on top of the screw head once you have finished and that makes it an even more practically perfect seal, though it does make it harder to remove the screw next time.
I suspect it is known by a different name now.
Hope you can help.
103717
 
Alan Surrey

Alan Surrey

Member
Messages
993
Thanks Mowlas. Have you tried it? At £43.99 its an expensive item to buy without a personal recommendation. It puts a few more pounds on my windscreen wiper repair bill !
 
Alan Surrey

Alan Surrey

Member
Messages
993
Felonious Crud

Felonious Crud

Administrator
Staff member
Messages
21,143
Alan Surrey said:
Where can I buy the substance I know as Dum Dum?
The tin I have had for decades has dried up and right now, for the first time in years, I need some.
It is automotive putty. A black substance that can be worked in the hand like plasticine or blu-tac but more flowing than either, more like glazier's putty in that respect. It seeks - flows into the tiniest spaces - and then it stays there, preventing moisture from passing through the space and unlike glazier's putty, it never really sets solid. Once you get it on your hands you probably need Swarfega or maybe an amputation to get it off. It is generally used to make a water tight gasket. If you were to insert a screw where it could be rained on (and this is what I am doing with my car's scuttle) you would want to make a little gasket of Dum Dum and place it under the washer. As you tighten the screw it compresses the Dum Dum gasket under the washer and the Dum Dum flows one way into the threads of the screw - no water can get through that way now - and the other way, it becomes compressed out to the edge of the washer so no water can get through underneath the washer either: practically a perfect seal! You can put a blob of it on top of the screw head once you have finished and that makes it an even more practically perfect seal, though it does make it harder to remove the screw next time.
I suspect it is known by a different name now.
Hope you can help.
View attachment 103717
Click to expand...
It is exceptional stuff. I have some in the shed which must be 30 years old. I should check to see if it's gone off.
 
philw696

philw696

Member
Messages
25,383
That really is a blast from the past.
My advice would be go into a paint refinishing shop that supply the trade and see what's available today but the above recommendations will do the job.
 
mjheathcote

mjheathcote

Centenary Club
Messages
9,038
I've still got a bit left in an old tin.
I recall they changed the formulation, probably due to some banned ingredient and it apparently wasn't as good.
Most of my tin is in various duties on my Stag.
 
Gazcw

Gazcw

Member
Messages
7,762
Alan Surrey said:
Where can I buy the substance I know as Dum Dum?
The tin I have had for decades has dried up and right now, for the first time in years, I need some.
It is automotive putty. A black substance that can be worked in the hand like plasticine or blu-tac but more flowing than either, more like glazier's putty in that respect. It seeks - flows into the tiniest spaces - and then it stays there, preventing moisture from passing through the space and unlike glazier's putty, it never really sets solid. Once you get it on your hands you probably need Swarfega or maybe an amputation to get it off. It is generally used to make a water tight gasket. If you were to insert a screw where it could be rained on (and this is what I am doing with my car's scuttle) you would want to make a little gasket of Dum Dum and place it under the washer. As you tighten the screw it compresses the Dum Dum gasket under the washer and the Dum Dum flows one way into the threads of the screw - no water can get through that way now - and the other way, it becomes compressed out to the edge of the washer so no water can get through underneath the washer either: practically a perfect seal! You can put a blob of it on top of the screw head once you have finished and that makes it an even more practically perfect seal, though it does make it harder to remove the screw next time.
I suspect it is known by a different name now.
Hope you can help.
View attachment 103717
Click to expand...
I think it is stuff like this now which is your only option.Dum Dum Strip
 
mowlas

mowlas

Member
Messages
1,732
Thanks for the prompter, Alan, and guys, for all the alternative suggestions.

This is a really good find and useful for so many other jobs around the house and garden, especially given its waterproofing and electrical insulation properties.
 
Gazcw

Gazcw

Member
Messages
7,762
I have heard of mixing silicone seal with corn starch 60:40 to make a mouldable substitute.
 
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