Extending furnace duct hose

[kpm]

I need to extend a furnace duct hose 3' to route around a water filter I've installed, and I have two questions.

My hose is 4" blue-gray non-insulated flexible fabric. Is there a good place to get a small amount of this online? I can't seem to find much online except super-high temperature (and super-high price) duct hose. I searched the forums and saw an earlier thread with this link https://www.dwincorp.com/product/4-x...t-duct-slp-10/. This looks like mine but it is out of stock.

Is there a standard way to splice this stuff or do I need to replace the whole hose? I'd rather not replace the whole thing if possible.

Thanks for any help.

[kpm]

I think I found some - Thermaflex manufactures S-LP-10 non-insulated fiberglass coated fabric air duct. It's not very easy to find online in small quantities. Most places want to sell at least 200 ft. at a time. I didn't find any local supplier either. I found a supplier in Illinois that sells 25' quantity and ships for a reasonable price - Long Supply.

As for the splice, the standard technique seems to use a splice connector collar, sealed with duct tape or other sealer, and clamped.