One of the ongoing projects I had to stop for a while was the repair and improvement of the starboard hull with a revised approach for a stronger and better looking deck-hull joint. For the history in this repair see the post of 15 March.
Before leaving the marina for an undefined period of time it was essential to laminate the first layer of fiberglass on the foam applied on the surface of the lower deck with the junction towards the hull. The reason is simple, the sun and the associated UV’s in Malaysia would destroy the foam after a few months if left exposed in the open like that. Talking about laying fiberglass, my policy is to always start with a layer of chopped strand mat (CSM) before applying the “piece of resistance” i.e. the woven roving of multi-axial cloth in this case. A first layer of CSM enhances the bond between the inner surface and the applied fiberglass layers. CSM provides local strength (random oriented fibers) but no longitudinal strength, for this reason it’s better to only use a low density layer. Unfortunately the local provider only had 350 gr mat available, I would have preferred 150 or maximum 200 gr instead. So 350 gr it became! Going back to the post of 15 March, I explained the issue with the foam I used and the issues caused by these unfused fibers! Meaning I still had to finish solidifying the total surface of the foam before laying the CSM on it, otherwise there would again have been horrible and enormous air bubbles between both. Running out of coloïdal silica (remember, all supply sources are closed because of COVID-19) I was forced to use micro balloons instead to thicken the resin. Consider that as feeding pigs with a top chef preparation, micro ballons are 5 to 6 times more expensive compared to coloïdal silica. But he, no other option, right? To ease the pain: it sands much easier :-)!
Working on large surface like that, it’s good to have an adapted tool. Not just to cover bigger surfaces at once but more specifically to put the compound in the appropriate quantity at the right place. I really needed a large trowel to be able to do this. During the fairing process the requirement will be even more critical. Back to Macguyver principles: if you can find it in the local hardware stores, you just do it yourself, right?
One of the things I still had to prepare before laminating the CSM was the provision for a shore power connector. Nothing fancy, these connectors only require a 6cm diameter opening where installed and some solid background to be screwed tightly in place. I could have just drilled a hole in the actual surface somewhere in the starboard scoop, but my concern was the exposure to water and the possibility to screw this device in place where there is only 4mm of glass available. So I elected to add some sort of wooden receptacle for a double purpose: the wood can serve as a base to screw the connector in and the shape can be adapted by inclination and shielding so water flowing from the deck down the scoops is deviated from the position where the connector is situated.
Then it was time to start laminating the CSM. I will not elaborate to much on the technique to do so here. The most important as always is preparation: cleaning and degreasing the surface, pre-cut the fiberglass mats, prepare small quantities of resin at the time (short curing period because of the heat). During application, be generous with the quantity of the resin so the CSM is well impregnated (no air bubbles) and can conform to the shape it is being applied on.
Normally, I would have continued with the application of the other layers of fiberglass right after this. With polyester you can laminate wet on wet, meaning you don’t have to wait for the surface to cure, sand it, clean it and then continue with the process. As I performed this work at departure day – 3 and I was out of fiberglass anyhow, I needed to finish the job with an intermediate fix: apply a layer of waxed gelcoat on the complete CSM surface with the roller to protect it from the UV radiations and to enable the polyester resin to cure. In addition, this gives some sort of pre-look of what the end result will be because of the predominance of white instead of raw polyester resin on the foam surface. A very limited artist impression one have to admit :-).
And here comes another surprise when we talk about the starboard hull. Another case of delamination, yes Sir! Hard to determine what the root cause, most likely it must have been a collision with a foreign object on the concerned area. The technique to determine where the fiberglass is no longer adhering to the core material is simple: knock on the surface with a hard object (like a wooden hammer) and listen to the sound it makes. Solid bond produces higher frequencies compared to delaminated parts. Using this technique I was able to draw the perimeter where the core is no longer attached to the outer skin of the sandwich construction.
The holes visible on the first picture might have been done in the past as an attempt to evacuate moisture trapped in the sandwich, that’s a technique used from time to time for this purpose. They have been filled with some sort of a compound after that. From their position above the waterline, the risk of water intrusion is limited. On the other hand, the previous owner must have had a reason to do so in the past, that reason will become clear in a future post related to the bow and the beam.
This section will have to be repaired the same way I did with the chainplate area of the starboard hull: remove the fiberglass in the contaminated area, bevel the perimeter with a 12/1 ratio and re-laminate the surface once the core has been assessed as good for further years of good service (no moisture, no cracks or decomposition of any kind). Work for when I will be back in the marina.
Last little tasks before leaving:
Stay tuned for more news on the last projects in relation to this first period.