Product Overview
Thermalcote 249 Thermal Joint Compound, 1 oz Tube with the Original Thermalloy Carton
Condition
New. The tube is bright yellow with its black screw cap in place, printed Thermalcote T.M. THERMAL JOINT COMPOUND on the face and carrying the Thermalloy Inc. double-T logo with DALLAS, TEXAS above the crimped tail. It ships with the white cardboard carton shown in the first photo, printed Thermalcote, Thermal Joint Compound, Thermalloy Inc., Dallas, Texas, 1 Tube, Net Wt. 1 oz., Part No. 249. The printing is sharp and fully legible end to end. The flat crimped tail is folded over unevenly and bent up at one corner, and a small pale trace of compound sits right at the seam; the closeup photo shows it plainly so you can judge it yourself. How much compound is inside cannot be seen from the outside of an opaque metal tube. Two tubes are on the shelf.
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Product Overview
Thermalcote 249 is Thermalloy's thermal joint compound, a white heat transfer paste made to fill the microscopic air gaps between a device case and its heat sink so the joint actually conducts instead of insulating. This is the 1 oz squeeze tube, Part No. 249, packed one tube to a carton. The printed Typical Properties panel on the tube reads color White, working temperature -40 to +204 C (-40 to +400 F), thermal conductivity.226 Btu/ft-hr-F (.0009 Cal/sec-cm-C), dielectric strength 300 Volts/mil at a.050 inch gap, cleaning solvent turpentine or mineral spirits, and shelf life indefinite unopened. Directions on the tube are equally plain: apply a thin, even coating to mating surfaces, then remove excess compound with solvent once the joint is secure. The tube is labeled Thermalloy Inc., Dallas, Texas, the name this line carried before it was sold under Aavid Thermalloy.
Key Features
- Part number: Thermalcote 249, carton marked Part No. 249
- Net weight: 1 oz per tube, one tube per carton
- Color: White, per the tube label
- Working temperature: -40 to +204 C (-40 to +400 F), per the tube label
- Thermal conductivity:.226 Btu/ft-hr-F (.0009 Cal/sec-cm-C), per the tube label
- Dielectric strength: 300 Volts/mil at a.050 inch gap, per the tube label
- Cleaning solvent: turpentine or mineral spirits, per the tube label
- Shelf life: indefinite unopened, per the tube label
- Markings: Thermalloy Inc. double-T logo, DALLAS, TEXAS
- Packaging: original white Thermalcote carton included
Applications
- Bench technician remounting a TO-3 power transistor to a chassis heat sink and wanting a thin, even film under the hardware
- Industrial electrician re-seating an SCR, bridge rectifier, or power module on its sink during a drive or control cabinet repair
- Ham operator rebuilding the pass transistor bank in a linear amplifier and redoing every thermal joint at once
- Vintage audio and test gear restorer who wants a period-correct joint compound for a rebuilt power supply section
Frequently Asked Questions
What temperature range does the label give?
The Typical Properties panel reads -40 to +204 C, which the tube also prints as -40 to +400 F. That figure is the manufacturer's own printed number, readable in the closeup photos. Anything beyond what the label states is not confirmed here, so check it against the datasheet for your application before use.
Is it electrically insulating?
The tube lists dielectric strength as 300 Volts/mil measured at a.050 inch gap. Treat that as the label's rating, not a substitute for a proper insulator: if your mounting scheme needs isolation, the mica or silicone pad still does that job and the compound fills the gaps around it. Not confirmed for any specific isolation requirement, so verify against your build's spec.
Is the compound still good after sitting this long?
The label answers it directly: shelf life indefinite, unopened. The tube in these photos is capped and packed with its carton, though the photos cannot show how much compound is inside an opaque metal tube, and the crimped tail is creased. As with any paste, knead the tube before the first bead and expect to lay a thin film rather than a heavy one.
What clears the squeeze-out?
Thermalloy prints the answer on the tube: turpentine or mineral spirits. The directions call for applying a thin, even coating to the mating surfaces, then removing the excess once the joint is secure. Use the solvent your shop already trusts around the surrounding finishes.
Why buy this single tube here instead of chasing an auction lot?
Because you can see exactly which tube arrives. It is photographed on all sides, the printing is legible, the carton is with it, and there are two on the shelf rather than a mystery crate of unlabeled grease that may be dried out. One ounce covers a great many joints, so a single tube is usually the whole answer rather than the first of ten you did not want. Shipping is $8 flat rate and free once your order passes $28, and orders leave our Idaho warehouse the same or next business day.
White paste out of Dallas, Texas, from the era when a heat sink joint was something you mounted by hand and checked with a fingertip. The label calls its shelf life indefinite, so this tube can wait in your drawer for whichever transistor needs it next.
