How To: We asked Hamish… how do you repair a stanchion on a fibreglass boat?
Is one or more of your lifeline stanchions coming away from its base? It’s a common problem but it’s vital that it’s fixed quickly. A repair with thickened WEST SYSTEM® epoxy and fibreglass will do an excellent job, as our technical expert Hamish explains.
There’s a lot of stress placed on the humble stanchion. Often knocked when docking, or shoved when setting sail, it’s not uncommon for them to weaken, or even wrench away from their base entirely. However, given the vital role that these posts play in crew safety, it’s essential that they’re fixed as soon as possible.
On a fibreglass boat, fixing a stanchion base with epoxy is a relatively straightforward procedure. Here’s my written step-by-step guide to assist you through the process.
Step 1 – grind away the damage
The first step is to take out the stanchion and cut back the hole to remove all damaged material. Once the damaged material is removed grind a 12:1 taper around the hole. Grinding a bevel around the edge will create an enhanced surface area for your epoxy bond, so that the repair is as strong and long-lasting as possible.
Step 2 – create and insert a backer
Make sure you wipe the area clean with WEST SYSTEM 850 Cleaning Solvent or clean acetone.
Then you’ll need to create a backer to laminate against. This can be plywood if you have access to the inside or a section of splash laminate. A splash moulding is created by waxing an area of the boat with a similar profile and laminating a single layer of woven glass fabric followed by peel ply. Once cured, this laminate can be released and cut to size with scissors. This splash moulding is flexible enough to bend and post through the hole (remember to remove the peel ply before inserting it) and pulled back to bond against the inner surface of the hull with G5 Five Minute epoxy thickened with WEST SYSTEM 406 Colloidal Silica. A simple self-tapping screw inserted into the centre of the splash will give you something to hold or even tie string to, to help you hold it in place. Leave it to cure.
Step 3 – prime repair area
Using a mix of WEST SYSTEM epoxy resin and hardener brush coat the tapered area. You will notice a strong colour change as the epoxy wicks into the exposed glass fibres in the polyester laminate.
Step 4 – apply thickened epoxy
Mix up some WEST SYSTEM epoxy resin and hardener and blend it with WEST SYSTEM 406 Colloidal Silica to a mayonnaise consistency. Use a small brush to apply this to the slight gap between the backer and the bevelled polyester laminate, pushing it well in and smoothing it around so that it fills any irregular shapes. This will aid with the bedding down of the fibreglass part of your repair and prevent voids forming.
Step 5 – apply fibreglass
Whilst the thickened epoxy in step 4 is still sticky, the next step is to mix up some more WEST SYSTEM epoxy but this time adding some WEST SYSTEM 402 Milled Glass Fibre Blend. Push this mixture into the hole with a mixing stick first of all, before working it into the hole with a brush, stippling to feather out any spiky bits of the fibre and remove any air bubbles.
Step 6 – apply your peel ply
To help compact and smooth out the repair, apply some more peel ply to the fibreglass mix when it’s wet. Ensure the peel ply is nicely wet out by the epoxy/fibreglass mixture. If you’re working in windy weather you may wish to apply masking tape to secure the peel ply.
That’s all there is to it. Once this has cured you can remove the peel ply, grind it back, fair the area with WEST SYSTEM epoxy thickened with WEST SYSTEM 409 Microsphere Blend before applying your gel coat and re-fitting the stanchion. You’ll find this is a sound repair that will last a long time.
Has the stanchion also damaged the side decking of your boat? Find out how to fix this by watching our stanchion base repair video by David Johnson.
Want to know more about fibreglass boat repair? We have a whole host of articles – take a look here.
Got a question for Hamish? Email us at firstname.lastname@example.org and your question may feature in a future edition of epoxycraft!
Image credit: Sailnet.com