Please select your home edition
Edition
Wessex Resins 2019 - Pro-Set - 728x90

421 Fire Retardant Additive for West System Epoxy Resin

by Jake Kavanagh 1 Aug 2019 12:00 BST
421 Fire Retardant Additive for West System Epoxy Resin © Wessex Resins & Adhesives

What is it? WEST SYSTEM® 421 Fire Retardant Additive does what it says on the tin - it retards fire. It is a heavy, non-combustible powder that is added to a fresh mix of epoxy.

Used for? An extra layer of fire protection in areas such as galleys and engine rooms, or anywhere there may be a risk of heat absorption that could lead to combustion, including cabins and saloons. It could also be used to line the coffer dams around skin fittings to prevent hoses being burnt through, or to run on partitions beside hot areas such as exhausts. It is especially useful if the partitions themselves are combustible, such as plywood bulkheads or galley headliners.

Mixing ratio: An easy 1:1 by weight. However, at this ratio the additive will greatly increase the viscosity of the epoxy so the resulting mix will need to be applied with a trowel or squeegee.

Hamish's Tips

"This is a very straightforward additive, so just follow the mixing ratio and be prepared to apply a thick layer of material," Hamish says.

"It will help to apply a coat of epoxy onto a properly prepared (degreased and abraded) substrate first to achieve better adhesion. When tacky, apply the epoxy/421 Fire Retardant Additive mix over the top. If you want to apply further layers of sound-proofing to the partition use peel ply during the application or wash the cured 421 Fire Retardant Additive down to remove the amine blush before sanding.

"Key the surface to promote good adhesion of the soundproofing, although peel ply does that automatically on removal. That's it - 421 Fire Retardant Additive will give additional peace of mind in areas of the hull with a higher risk of fire."

Typical application

We wanted to enclose the engine wet exhaust that runs along the floor between two bunks, so needed a plywood partition. To fireproof the plywood beneath the soundproofing, we decided to treat it with a coat of 421 Fire Retardant Additive.

Related Articles

Stunning colour tints for epoxy creations released
An exciting line of liquid colours has been released to add bold and beautiful tints to epoxy Specifically designed for epoxy river tables, jewellery and other crafts as well as sporting equipment like surf, skate and snowboards, the beautiful selection of colours come in two thematic packs, Soft and Vivid. Posted on 1 Aug
DNV GL approval for Pro-Set epoxies
Lloyd's Register approval for WS resin and hardener combination PRO-SET epoxy systems have been approved by DNV GL for use on ships, yachts and as 'laminating resin for construction of laminates made of fibre reinforced plastics'. Posted on 14 Jul
Building a wooden dinghy with epoxy resin part 3
Completing the hull and making an amazing spinnaker chute Steve Goodchild wanted to avoid nailing the planks to offset chocks set against the frames, as this would leave multiple rows of nail holes visible in the wood. Instead, he decided to glue the entire hull together using thickened epoxy. Posted on 11 Jun
Chandleries currently open stocking epoxy resin
Places to buy West System products during June 2020 in the UK We're all eagerly anticipating the reopening of retail outlets. In the meantime, if you're looking to stock up on your favourite epoxy brands, here are some WEST SYSTEM®, PRO-SET® and Entropy Resins® epoxy stockists who we know are currently open. Posted on 5 Jun
WEST SYSTEM® epoxy set to go sub-orbital
NOVA 2 rocket within ten months of its first launch A NOVA 2 rocket being developed by Starchaser is within ten months of its first launch. This one-seater rocket is a significant step towards future plans which include a rocket capable of taking two passengers with the pilot. Posted on 1 Jun
West System used to create bullet coat racks
New lockdown project using epoxy resin Dee (David) Caldwell has spent his lockdown creating bullet coat racks. Using locally sourced WW2 bullets he's collected at Medmerry, West Sussex, and wood from a cedar planted by Capability Brown, he's started a new business in his garden workshop. Posted on 13 May
Electric boat's sustainable construction
Bio-based infused epoxy resin, recycled PET, and basalt/flax fibres RS Electric Boats, the sister company to RS Sailing, unveiled its electric RIB earlier this year, a boat that's said to be the highest level of sustainable construction of any boat in its sector. Posted on 2 May
WEST SYSTEM 105-K Glass Fibre Boat Repair Kit
The upgraded kit comprises everything needed to fix minor cracks, holes and punctures Wessex Resins is delighted to announce it has improved and updated the WEST SYSTEM® 105-K Glass Fibre Boat Repair Kit. The kit comprises everything needed to fix minor cracks, holes and punctures as well as refit and replace hardware on a boat. Posted on 16 Apr
Wessex Resins & Adhesives joins 1% for the Planet
Donating to Protect Our Winters UK Wessex Resins and Adhesives is delighted to announce it has donated 1 per cent of its annual turnover for the ENTROPY RESINS® product range to Protect Our Winters UK. Posted on 9 Apr
Building a wooden dinghy with epoxy resin part 2
Strip planking the hull, and making an amazing wooden mast "You don't build your own boat to save money," Steve explains. "You do it for the sheer satisfaction of the craftsmanship involved. For what I paid in raw materials I could have bought several second-hand boats, but where is the fun in that?" Posted on 18 Mar