Installing a Floor Bearer

The IDRA 14 isn't known for its high precision build. While prepping this area a number of bubbles in the original fibreglass opened up. This is not a worry, it's not uncommon to find water has worked into these so there's no harm to allow them to dry out fully before addressing them.

To fill the voids mix up some epoxy resin and add in some filler powder. This can then be used to fill the voids. On small sections this will often be enough. For larger voids or ones in structural areas, fill and then add a layer of fibreglass over the top.

Our first task is arguably the most important. We have to remove the old bearer as well as any paint, and try to get down to the fibreglass layer. If there is gelcoat on the boat this should be removed for the strongest bond to the hull.  The quickest way to do this is to use a multitool and cut out the old bearer,then an angle grinder with a 60 grit sanding disk to tidy and flatten the area. Be careful not to go deep cutting through the hull with the grinder.  Fear not though because if you do, it can be repaired too.

When prepping for epoxy it is always best to clean the boat thoroughly before you do any sanding. This ensures no contaminants will be driven into the hull which could cause an issue or sub par bond later. Once all paint and gelcoat is removed make sure you get rid of all dust and wipe the area down with acetone.   

You can see the new core being added to the centreboard case. This is made from a closed cell polurethane foam which has added choppedstrand fibreglass. This type of core is strong, durable and has better water resistance than a lot of woods.

To stick it in, it was coated with West System Epoxy which was thickened with their low density filler. To speed up the process and avoid using clamps four small blobs of five minute epoxy was also added to the back. These blobs act a bit like a spot weld holding the piece in place while the rest of the epoxy cures.

The reddish filler you can see is the low density filler which is used to run a fillet around the edge. This will remove sharp angles and corners which the fibreglass cloth doesn't like to bend around. It also helps spread load into the existing structure better.

Once all the filleting and smoothing is complete it's time to add your fibreglass. Here you can see a medium weight (450g m2) biaxial fibreglass being added to our new support.  The biaxial cloth is much stronger than the thinner fibreglass tapes or chopped strand and really helps to "stitch" together the new and the old.

You can see as the epoxy resin is being added the cloth goes transparent. This is a good indicator to see if you have enough resin going on to the cloth. When we're done you. should be able to see our work below this layer.

With our new centreboard case support in and our fibreglass thoroughly wet out we can add in our new floor bearer. This one has been made by putting a layer of 200g plain weave cloth on either side of a closed cell PVC foam. While the foam isn't as strong as wood it is rot resistant and will last many years. The glass layers as well as the fibreglass which will be added later on to hold them in place will give the foam plenty of strength.

To bond the bearer we add a thickened mix of epoxy resin and low density filler everywhere it makes contact with the boat. Because this will take a while to set and we don't want things moving about we've added some more small blobs of G5 five minute epoxy. 

While pushing the bearer into place some squeeze out of thickened resin is to be expected. This should be rounded off to create a fillet joint. The fillet gives the glass a nice round transition from the floor bearer to the hull rather than a hard 90° corner. This disperses the loads better into the hull and helps prevent "hard spots" forming in the hull.

The fillet is quite important to make the joint strong so add more thickened resin if needed to ensure a nice round, consistent join.

Make sure you fillet each corner and not just where the bearer meets the hull. Here you can see a fillet joint being created to tie the bearer to our case support. Again this will provide a stronger transition for the fibreglass, spreading loads.

Filleting done, five minute resin set and things starting to harden it's time to move on. You can just make out here that the area which will receive the new glass has been "primed" with epoxy. This will hold the cloth in place and prevent it peeling away.

Now it's time to push the cloth into all the little corners and tricky areas. Do this carefully and methodically because we don't want to find any gaps under our new glass when everything is set. Our aim is to have no bubbles or weak points. Be careful not to put too much pressure on the fillet joints. They won't have set by this stage and we can easily squeeze away all our good work from earlier.

This glass will stitch the bearer in place and give it the extra strength needed to support the weight of crew hopping about. You can just make out on the left that the cloth has already started soaking up the resin we used as a primer. As you manipluate the glass into place start adding resin to wet out the fibres fully. Remember we are looking to make the glass transparent.

With the glass wet out fully now is the time to check for gaps and bubbles. Make sure everything is evenly wet out and well stuck to the hull. Do this by firmly pushing the glass down with your brush but be gentle and slow when lifting the brush so that you do not pull the glass back off.

We don't know who invented peel ply but they are geniuses. It’s a sacrificial layer that helps feather rough edges of the new glass into the rest of the boat, removing the pattern of the glass cloth giving a nice consistent factory style finish. Best of all it removes the need to wash and sand the new fibreglass.

When you're happy your glass is consolidated, cut strips of peel ply and place them on top of everything you’ve done. Peel ply does not like corners so cut smaller strips to accommodate different sides rather than one piece to cover multiple axis. Wet them out just like your glass until it goes transparent. You can see peel ply has a red tracer. This helps to see where you've added it and is a reminder to pull it off after everything has cured.   

You can see here we've left some areas of peel ply dry. This is hugely important as it allows you to grab hold of and pull off this sacrificial layer. This rest of the cloth is saturated and consolidated down to the boat and new bearer. It's important to make sure the peel ply is wet but not so wet that it is glassy or there are puddles showing. It will actually float in a puddle of resin which only adds weight and reduces strength, You'vre looking to wet it out until it is matte look rather than a gloss look.

Here you can see everything is now almost finished. We can see the red tracers in the peel ply are covering all our hard work. We've left plenty of it dry to give us something to hold on to while pulling it off. Everything is stuck down to the boat and there's nothing to do now but put the kettle on and congratulate yourself on a job well done.   

Next day we removed the peel ply, trimmed any jaggy bits on the top and filled the top 5mm of the bearer with thickened resin. This will protect the foam for many years and give us a nice surface to sand making it flat for our floor to sit on.

Small areas, as can be seen here on the case support, where there are small inconsistencies are left behind when there are gaps or bubbles under the peel ply. No need to panic and small sanding followed by some thickened resin will make short work of them.