: But, a question, should I do
: test pieces just to check the pump ratio correctness? If so how
: much is sufficient, one pump each, two? How do I check the
: quality of the glass after it hardens? Do I assume that if it
: gets hard it is correct? Unfortunately, I don't know what I
: don't know.
: Thank you,
: Randy

Hi Randy

The simple way to test your pumps without waste is to get two large syringes or small cylindrical containers (old 35mm film canisters are good), prime the pumps, pump the resin into one and the hardener into another and compare the quantities. The syringes are of course marked. A ruler works too.

Try not to let you mind wander when you are counting pump strokes for mixing. I remember on TV seeing a hull that had to be scrapped on, if I remember correctly, an Americas Cup yacht. Someone had forgotten to add hardener to one batch of epoxy during the layup and the whole hull delaminated along the one side during construction. That was not a popular guy.

As a first timer you will be thinking that you need to get that epoxy onto the glass before it starts going off. This can lead to rushing the mixing process.

Until you start becoming more confident mix smallish quantities and mix them very well. Poor mixing has given me more grief than anything else. For wetting out large surfaces about a paper cup's worth is probably a good starting quantity until you figure out your natural working speed.

If you pour the mixed resin into a flat pan after mixing it will react more slowly. In a cup it will go off very fast.

When wetting out one can over-work an area thinking it is not wetting out enough. Too much rolling or squeegee can create a foamy micro bubble paleness in the resin. Don't try to force the first coat of resin in. If it is warm enough it will penetrate if allowed a little time. Saturate an area, mix the next batch, saturate the next area, keep looking back, you will notice that an area behind has gone nicely transparent, leave it a while longer to fully penetrate into the wood. (spread thinly on the hull the resin will allow you more time than you may at first imagine). Finally, when you feel the wood has had time to draw in as much resin as it wants, It is time to move back with a squeegee and (evenly but gently) squeegee out any excess resin. This will reduce weight.

If the cloth is lying flat against the wood you have done your job.

There is a misconception that sanding is needed between epoxy fill-coats to get a fairer surface.

This is wrong. If you sand between fill coats you will abrade the glass fibres of your cloth. The point of fill coats is so that you can sand afterward without damaging the cloth.

The following few checkpoints may help you with your approach to the job and enable you to relax and enjoy what can be a bit of a fraught process the first time out.

The key to good saturation is:

1. a warm workshop, a warm hull and warm cloth. It can help to roll out the cloth onto the hull and let it warm as you heat the workshop.

2. For the first saturation coat - Heat the workshop - then switch off the heating - then apply the saturation coat in falling temperatures. (to avoid outgassing). (sun through a window on the hull can cause outgassing) Outgassing is not a problem with fill-coats.

3. Measure resin and hardener correctly - mix very well - pour into flat container - apply as evenly as possible, leaving enough resin for a little wood penetration - don't overwork - squeegee when cloth is clear and wood has taken what it wants, but before the epoxy reacts.

4. When wetting out - I usually start a couple of feet from one end of the boat - work to the point at that end (to get the cloth nicely attached to the hull) - then keep working towards the other end, thus keeping a wet end between batches. (ie: don't start in the middle of the boat). As you work down the hull a (gentle) pull on the cloth from time to time will ease out any wrinkles that may want to form. (The cloth becomes quite compliant when wet out).

5. It is ideal to apply fill coats during the chemical bond window of opportunity. Rule of thumb-nail - when the epoxy has hardened to the point where it will no longer take a fingerprint, but can still be dented by a thumbnail, it is ready for another coat. - I try to get my saturation coat on at about midday, my first fill coat goes on sometime that evening or night, and then get up every four hours or so during the night to check if it is ready for the next coat, etc. My wife hates me at these times. - The point of fill coats is to fill, so no squeegeeing of excess here. I use a roller and tip off with a brush. (An observation: You are more likely to avoid the dreaded blush if you can get to the fill coats each time as early as possible during the re-coating windows.

6. Get everything sorted before you start the job. You do not want to leave it for any reason during the saturation stage. - Make sure someone is minding the kids - and if guests drop in be prepared to be rude (No stopping for tea and a chat in the middle of the job). - Make sure you have everything you need before you start and that you can get to it without panic. - Put on your vapour mask and relax before you start. - Don't rush - If you work away steadily and in an organized way you will be fine.

For me glassing is the chore aspect of the job. It just has to be done with as little fuss as possible. Once you get started it is actually less of a drag than in the pre-thinking.

Have fun

Et