Thermwell logo


Jan 29, 2019

Frost King Acquires PortaSeal

Mahwah NJ – Frost KingPatio Door Insultation Skrink Kit

Mahwah NJ – Frost King (Thermwell Products Co., Inc.) has acquired PortaSeal LLC of Morristown NJ, manufacturer of weathersealing products for more than 55 years, according to Mel Gerstein, a principal of Thermwell who oversaw the purchase. PortaSeal’s best-known product is Gara-Seal, a rigid vinyl strip with a flexible self-adjusting vinyl flange which seals the top and sides of garage doors. The company also makes Magnet-Stop, a full doorstop which gives a refrigerator-like seal to metal clad exterior doors; plus several other popular weatherseal products

The product line will be marketed in conjunction with Thermwell’s best known brand, Frost King…for many years America’s leading brand of do-it-yourself weatherstripping and pipe/duct insulation.

In addition to Frost King, Thermwell’s family of products now includes Mortite, the premiere name in rope caulk for over half a century; W. B. Marvin, pioneer maker of adjustable metal window screens and fans; Seal-Rite automotive weatherstrip products; Regent, maker of a full line of consumer and contractor tapes; Lever, the leading US designer and manufacturer of slitting, cutting and winding machinery; Filmpak Industries, extruder of polyethylene sheeting, drop cloths, trash bags and shrink window kits; and Kraver, manufacturer of screening.

Thermwell has offices and factories in Mahwah NJ and Sparks NV, with production and distribution facilities throughout the country.

For further information, contact
Mel Gerstein
Thermwell Products Co., Inc.
(201) 684-4401