MAS FLAG Thick Epoxy Resin

Resin Filleting, Laminating and Gluing Resin F.L.A.G. Resin is a “medium” body resin specifically designed to perform as an adhesive and structural laminating foundation. The medium viscosity allows for the incorporation of fillers when fairing putties, gluing slurries and filleting systems are required. F.L.A.G. is more reactive than our Low Viscosity Resin when mixed with Medium Hardener. This keeps fillets and fairing from slumping. F.L.A.G Resin is next day sand able when cured at 60 degrees F. and higher with Medium Hardener. F.L.A.G Resin may be used with all MAS Hardeners, however, for filled applications we recommend Medium Hardener

FLAG resin like all our other resins is a no blush no wax formula so there is no washing down between coats. FLAG must be mixed at two parts resin to one part hardener by volume or weight our pumps are pre calibrated (we recommend digital scales brought from the super market and covered with cling film for any long project) Mix the hardener and resin well, once mixed additives such as workshop mix or W.S M 10/20 can be added for gluing or fairing (see additives for more information).

Use. Flag can be used with slow, medium or fast hardeners  for gluing most substances. It can be used just with its hardener added to go over any cloth work and build depth and thickness and fill in any weave that has been soaked out or to build a barrier coat.

With fillers such as silica micro balloons W.S 10/20 etc it can be used to fair out areas and help bring back the shape to a hull or object when used with Medium hardener it has very good anti slump properties 

When gluing adding workshop mix or other additive helps fill voids  however on large areas we recommend drilling of small holes which allow the epoxy to push through like worms these set to become epoxy nails and help prevent  pockets of air from being trapped in the layers 

When adding powders to make putty or slurry remember to always leave a shine on the mix otherwise it may be epoxy starved and crumble and not cure (do not make the mix to dry) 

When moulding or filling large voids do so in small layers to avoid over heating

Measured Properties Empirical Calculations or Physical Properties
Resin Viscosity 3000-3400 cps Hardness Please Call 01205 760014 or mob 07904446306  For More Information.
Colour 1 Gardener Max Tensile Strength
EEW 190-200 Tensile Elongation
Tg 140oF Compressive Strength
Mix Ratio 2:1 Resin: Hardener
Peak Exotherm (30g batch) 360oF
Pot Life (30g batch) 15 minutes

MAS EPOXY comes with a choice of three different hardeners. Each hardener will produce a blush and wax free finish allowing easy over coating with further layers of epoxy, epoxy and cloth or final paint varnish finish.


MAS FAST HARDENER can be used as an accelerator for MAS Slow and Medium Hardeners when customized cure times are required. Appropriate applications of MAS FAST hardeners formulas include hardware bonding, spot filling, and fairing. Additionally, the superior bonding strength of MAS FAST hardener mix is ideal for high strength secondary bonding applications such as structural tabbing and repair lamination’s.

The rapid cure time of MAS FAST hardener allows overnight curing in low temperature conditions so your project can be sanded next day

We do not recommend mixing more than 140 grams. of formula unless rapid application techniques are incorporated.

An induction time of 1-2 minutes is recommended prior to application of formula. We have found the low viscosity of MAS FAST hardener allows for fast wet-out of the heavy reinforcing fabrics often used in repair applications. MAS SLOW or MEDIUM may be blended with MAS FAST to retard the mix of the MAS FAST  hardener when customized cure times are required.

Remember Surfaces coated must be carefully prepared prior to re coating and bonding dust and grease free and a good scratched key over the whole area to be bonded



MAS MEDIUM hardener has a moderate gel and thin film set times providing great advantages when filleting and fairing. MAS low vis and flag resins when mixed with Medium hardener and the appropriate thickener will gel and set quickly enough to avoid draining out and sagging, while still giving you the time to get the job done. We recommend this hardener when “overnight” sanding is more important than continuous laminating and open time (as provided by MAS SLOW Hardener)

MAS MEDIUM hardener will also provide a beautifully smooth void free finish with great resistance to milking out during application and fogging in critical clear coating applications..

Cure speed gelling and thin film set can be adjusted by adding either slow hardener or Fast hardener as needed but the mix must remain 2 parts resin to 1 part hardener

This is our standard hardener that we recommend for all gluing and fairing work , provided the customer is experienced enough and happy to work at a faster rate. However when wetting out multiple thickness of cloth we recommend slow hardener to ensure the epoxy hardener mix has properly wet out before it starts to gel


MAS SLOW Hardener

MAS SLOW hardener is a hardener that will give you a working pot life of 30 – 35 minutes , when used with MAS LOW VIS or MAS FLAG resin at a ratio of 2 parts resin to 1 part hardener it gives a good extended gel time allow you to control the application

Special features exhibited by this product include blush free surfaces, good ultraviolet stability, smooth finishes in cured films, excellent osmotic resistance, and the ability to cure under high humidity

We recommend MAS SLOW hardener when working on large areas and on cloth were we want the maximum amount of penetration before gel starts. slow hardener can be mixed with our other hardener to get the correct working time for your application

As with all our hardeners MAS SLOW is blush and wax free there is no need for any wash down between coats (if the surface can be marked with your thumb nail , then you can go straight on top if it can not a simple roughing or abrasion is needed to give a good key)

Use: If you are a beginner to the use of epoxy we recommend that you choose slow hardener, this gives you an extended pot life enabling you to take time on your work and giving you the opportunity to correct any thing along the way. When doing large areas or when large mixes are needed always consider MAS SLOW hardener first.

Caution: Not recommended for use below 8 degrees C unless cure time is available.

This means that you simple have to give the product longer so if it is below 10 degrees C yes it will work but you have to wait but as a policy we would recommend a quicker hardener the cooler it gets

Remember you can mix MAS SLOW with MAS MEDIUM AND MAS FAST to achieve a work and cure time you want but the mix ratio must remain 2 parts resin to 1 part hardener

Black Bear Boating & Leisure will deliver any paid for goods in the quickest possible way, usual delivery is 2/3 days however were we are sending goods overseas (this means across any water) this period may be extended up to two weeks or longer at the company’s discretion.

The company has an ongoing belief that good customers expect and deserve a top class service.
In the UK, any problem reported to us on delivery will be dealt with in the following manner: