Thermal Barrier

[William Alexander]

We require to coat mild steel bolts with a nonconductive/thermal barrier the thickness of coating requires to be thin enough for the threaded end of the bolt still to except a nut, temperature range -10 to plus 30 degrees, so quite a small range, and the coating requires to be anti corrosive, any surggestion as to materials and best process to appliy

please William Alexander

[plasmajet1990]

(10-22-2008 07:53 PM)William Alexander Wrote:  We require to coat mild steel bolts with a nonconductive/thermal barrier the thickness of coating requires to be thin enough for the threaded end of the bolt still to except a nut, temperature range -10 to plus 30 degrees, so quite a small range, and the coating requires to be anti corrosive, any surggestion as to materials and best process to appliy

please William Alexander

Hello,

I suggest you to use Al2O3 (Metco 101NS, Metco 105NS.........) with the plasma spray process.

Regards,
Ion

[Gordon]

Hi William

to the Surface Engineering Forum.

Not really sure what you are after here, may be you can fill us in with a few more details.

I don't think a thermally sprayed ceramic coating or for that matter any other thermal barrier coating system will work on a thread/nut mating surfaces effectively.

Just thinking aloud, assuming a panel separating hot side from cold side, fasteners in this case steel nut and bolt provide unwanted heat conduction path. Ideally I suppose, fastener could be made from more thermally restrictive materials like plastic or ceramic . Possibly just placing a insulating cap over nut and/or bolt end should be effective and relatively cheap solution (you are also not so restricted so much by the thickness of insulation). Coating bolt and possibly nut I think will be expensive and not very effective.

[William Alexander]

(10-22-2008 09:56 PM)Gordon Wrote:  Hi William

to the Surface Engineering Forum.

Not really sure what you are after here, may be you can fill us in with a few more details.

I don't think a thermally sprayed ceramic coating or for that matter any other thermal barrier coating system will work on a thread/nut mating surfaces effectively.

Just thinking aloud, assuming a panel separating hot side from cold side, fasteners in this case steel nut and bolt provide unwanted heat conduction path. Ideally I suppose, fastener could be made from more thermally restrictive materials like plastic or ceramic . Possibly just placing a insulating cap over nut and/or bolt end should be effective and relatively cheap solution (you are also not so restricted so much by the thickness of insulation). Coating bolt and possibly nut I think will be expensive and not very effective.

Thanks for your reply, I take your point as to the threaded section of the bolt, however would it be possable to coat the shaft of the bolt,and may be the threaded section whith a reletivly thin coating of non conductive/heat resistant material

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Thanks for your reply, I take your point as to the threaded section of the bolt, however would it be possable to coat the shaft of the bolt,and may be the threaded section whith a reletivly thin coating of non conductive/heat resistant material

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Sorry for the double entry, still learning

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(10-22-2008 08:43 PM)plasmajet1990 Wrote:  

(10-22-2008 07:53 PM)William Alexander Wrote:  We require to coat mild steel bolts with a nonconductive/thermal barrier the thickness of coating requires to be thin enough for the threaded end of the bolt still to except a nut, temperature range -10 to plus 30 degrees, so quite a small range, and the coating requires to be anti corrosive, any surggestion as to materials and best process to appliy

please William Alexander

Hello,

I suggest you to use Al2O3 (Metco 101NS, Metco 105NS.........) with the plasma spray process.

Regards,
Ion

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Thanks for your advice I will contact a supplier

[landemarre]

(10-22-2008 07:53 PM)William Alexander Wrote:  We require to coat mild steel bolts with a nonconductive/thermal barrier the thickness of coating requires to be thin enough for the threaded end of the bolt still to except a nut, temperature range -10 to plus 30 degrees, so quite a small range, and the coating requires to be anti corrosive, any surggestion as to materials and best process to appliy

please William Alexander

Probably no answer in thermal spraying for your ask.

[Gordon]

Hi William

Quote:Thanks for your reply, I take your point as to the threaded section of the bolt, however would it be possable to coat the shaft of the bolt,and may be the threaded section whith a reletivly thin coating of non conductive/heat resistant material

To be honest, I can't really see what you are trying to achieve and this makes it difficult to give sensible suggestions, though I understand if you can't give too much info away

Yes, you could thermal spray or paint on slurry mix and bake a ceramic coating. But I would mask and not coat the threads where the nut goes. Plastic or resin coatings may also be an option, which would be a lot more conformable if coating the thread.