Yoramy wrote: ↑Thu Jul 05, 2018 9:21 amThe top glass layer at the bottom of this bilge seems to have been poured on top of the external hull layers. There is actually no space between that top delaminating layer and the bottom one. Yet if I push a sharp tool in between them, the top layer can be slightly lifted with some effort. So there is no space to inject anything there.
If you can lift the top layer, then there is space for some epoxy. Just inject as much epoxy as you can get in, any excess will squeeze out. Any extra bonding is worthwhile to achieve.
You need powder bonded mat. This is the reason.
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Necessarily the individual strands of glass that make up the mat need something to bind them together. In conventional emulsion bound CSM the binder is broken down by the polyester or vinylester resin it is designed to be laminated with. However, the binder used in conventional CSM is not broken down by epoxy resin meaning the individual strands all stay together in their original mat making the CSM impossible to laminate with properly. 'Powder Bound' fibreglass matting (CSM) is designed for use as chopped strand mat for epoxy resin, using a powder based binder that does not need to be broken down in the same way as emulsion bound mat, making it essential for use when laminating with epoxy resin, either making a mould or a part."
Peel Ply is used to pull the excess resin through it and peel it off the surface as it removes the excess epoxy along with the wax surface that forms. There alternatives for Peel Ply and Mr Google suggests polyester dress liner fabric or Rip Stop nylon.
With regard to the first layer of mat, you can fit it externally and support it with the Peel Ply or the alternative. Tape both top edges to the hull and if need be use some cardboard for extra support. The Peel Ply and cardboard will be thrown away
The West epoxy guide suggests this wet method for laminating.
By working with small quantities of epoxy, it is possible to work at a comfortable pace over quite large areas to be reinforced.
1. Prepare the surface for bonding as discussed in surface preparation (page 10).
2. Pre-fit and trim the cloth to size. Roll the cloth neatly so that it may be conveniently rolled back into position later.
3. Roll a heavy coat of epoxy on the surface.
4. Unroll the glass cloth into position over the wet epoxy. Surface tension will hold most cloths in position. (If applying the cloth vertically or overhead, it is possible to wait until the epoxy becomes a little tacky). Work out wrinkles by lifting the edge of the cloth and smoothing from the centre with a gloved hand or a squeegee/spreader. If cutting a pleat or notch in the cloth, lay it flat on a curve or corner, make the cut with sharp scissors and temporarily overlap the edges.
5. Any areas of cloth which appear to be dry, (white in appearance) apply more epoxy with a foam roller.
6. Remove the excess epoxy with a squeegee, using long overlapping strokes of uniform pressure. The object is to remove the excess epoxy that may allow the cloth to “float off” the surface but avoid creating dry spots by exerting too much pressure on the squeegee. Excess epoxy appears as a shiny area while a properly wet out surface appears evenly transparent with a smooth cloth texture. Subsequent coats of epoxy will fill the weave of the cloth.
Hope all of this explains how to progress now.