Preparing hulls for glassing

More Sanding

Posted by Paul

I spent a few hours yesterday and again only a few hours today sanding the touch ups and hole fills back down and generally cleaning up the hull ready for glassing. I have found that my idea to remove the peel ply at the last possible moment so that any spills of resin, glue, filler etc don’t have to be sanded/ground away was not such a good idea. I have barely spilt anything on the panels although I may spill some resin when glassing but by then all the peel ply needs to be removed anyway. The downside to the idea is that if you remove just a strip to fill the gaps as I have, if you haven’t trimmed back the ply enough you will invariably need to sand over the ply. Then when it comes to removing the ply, the sanded sections don’t come away cleanly enough and ironically the only way to remove the residue is to sand it off. This is far more work than I would have had to clean up any spills had I completely removed the ply at the start of the job.

So on the second hull I will certainly be removing the peel ply just after the hull panels are glued to the bulkheads maybe even before that, as the insides need to be removed before they are attached to the bulkheads. I still have the ply in place on the inside with just enough removed to attach each panel to the bulkheads. I will report later if this was of any benefit. I guess getting into hard to get to places to remove spills may be harder on the inside and I did manage to drip a lot more resin on the inside mostly through the gaps as I glued and filled the panels to each other.


Sorry but I didn’t have the camera so had to use the phone so there are no enlargements of these pics, but take my word for it, the sanded edges of the peel ply are a bugger to completely remove, it is extra work you can do without and sanding is not a pleasant job to start with.

I am pretty sure now I have the hull as smooth and fair and filled as well as I can. In fact I think (as usual) I am being too pedantic because any imperfections, as tiny as are left, will be filled with resin when glassed or with filler when bogged. At some point enough is enough, and as there are a number of layers to come there is no point being ultra ultra picky at this stage.

Some time this week, I will get some peel ply to put over the glass when wet to minimise the keying required for the bog, although I believe I may be able to get the first layer of bog on whilst the glass resin is still “green” (hasn’t yet fully set) and achieve a chemical bond so the peel ply may not be needed. It may depend on how much help I can get from friends. I am also waiting for a cool change. The lower temperature (if we get some) gives more working time to the resin. It is forecast to be 30 again tomorrow.

Before glassing it will take me a day or so to cut all the glass and do a dry fit to be sure I have the glass for the job correctly in place and, marked so that it is easy to figure where it should be on the day rather than being under pressure with setting resin and scratching my head trying to put another jigsaw puzzle together. I probably harp on it, but a little pre preparation saves a lot of stress. It may take a little longer but if you make a mistake because of lack of preparation it will take heaps longer and cost more to fix.

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