Fairing is the stage that separates a hull that's structurally sound from one that actually looks and performs the way it should. It's also the stage most builders underestimate, both in how much material it takes and how much dust it generates — get the right compound and technique and it's a straightforward, if not exactly quick, job.
What Fairing Is Actually For
Fairing isn't about strength; that job's already done by the time you're fairing. It's about taking out every low spot, high spot and print-through left by the structural lay-up, so the final surface reads as one continuous fair curve rather than a patchwork of the panels and layers underneath it. Skip it, or rush it, and every imperfection shows up under a coat of paint, when it's far too late to fix cheaply.
Choosing Your Fairing Compound
MAS Fairing Compound is mixed at a simple 1:1 ratio, and uses colour-changing verification so you can see at a glance once a batch is properly blended — useful when you're mixing small quantities repeatedly through a long fairing session and consistency matters. It's also formulated so the dust falls as you sand rather than floating in the air, which genuinely changes how tolerable a big fairing job is to work through, both for your lungs and for how much of the workshop ends up coated in fine dust afterwards.
Building Up in Stages
Don't try to fair a big low spot in one thick application. Build it up in stages, letting each layer cure before adding the next, and leave your final layer slightly proud of the surrounding surface rather than trying to get it dead flat straight off the applicator — that's what the sanding stage is for. Once you're through the heavy fairing compound, MAS Workshop Mix 10/20 is worth reaching for as a final lightweight, easily sanded layer over the top. It's a good decorative covering coat over heavier fillets already built up with fairing compound or Workshop Mix, sanding down to a smooth base with far less effort than the heavier compound underneath it.
Sanding Technique
Work through your grits progressively rather than jumping straight to a fine paper on a rough surface — you'll spend far longer trying to remove scratches from too coarse a grit than you would have spent working through the sequence properly. A long sanding board rather than a small block will help you find and correct the low spots a short block skates straight over, since a longer board only contacts the high points until they're brought down to meet the rest of the surface.
Safety While You Sand
10/20 is a very fine powder, so wear a light dust mask and eye protection when mixing it, and treat the sanding stage itself with the same care — fine epoxy dust isn't something you want to be breathing through a long session. We've covered the fuller PPE picture, including what's genuinely worth wearing and what's overkill, in our epoxy safety guide.
If you're planning a fairing job and aren't sure how much compound to order, get in touch via our contact page and we'll help you work out a sensible quantity for the area you're covering.
