2300° F is the max temp rating, and operating temp rating is closer to 2200° F, which is great for most things..., but not everything.  

Forge metal welding heats can exceed these temperatures, in this application, consider coating the wool with ITC-100 to reflect firebox heat back into the firebox, or using the 2300° wool as a 1' backing layer, with a layer of 2600° wool next to the fire.

Actually I recommend even coating 2600° F wool with ITC 100 too for the increased efficiency, faster heat-up times, and the elimination of the potential long term exposure risk with fibers becoming airborne and inhaled.  It quickly saves more than it costs with efficiency gained, and the peace of mind is of even greater value.

We used to only sell 2600° blanket.  The only downside to 2300° blanket is its higher cost.  In applications outside of forge metal welding's fire-exposed surface, many other applications can be well served by the 2300° wool.

NOTE:

• Wool will shrink and lose mass (appearing to evaporate) when exposed to heats exceeding tolerances over time, with concerns of lost fiber having become airborne in the absence of ITC-100.

TIP:

•  sprayed onto the blanket and fired will stiffen up, making the step of applying an  top coat easier, and you are able to prevent compressing the wool during this process, important in maintaining optimal insulation value.

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