Laminate schedule

[jfblouin]

I will build a 22 feet boat with 4 or 5 or 6 (depend of location) layers of Combo Roving-Mat 1808 over a male mold. I use polyestere resin.

Can I apply 2 layers in the same time?

Can I apply 1 layer in morning and a other in evening?

Can I use less than 1% of MEKP for rise the time before resin freeze?

How long can I brush resin before it will be "too freeze"?

Does some one have a gel time vs % of MEKP chart?

How max long I can wait betwen apply layer? (1 day, 1 week,or more)

What is the best applicator (roller, brush, foam brush)?

Can I sand GRP between layer if I have somes "rebel hair" of fiberglass to have a more flat next layer?

Thanks for answer

[gonzo]

Gel time and all other specs you can get from the resin manufacturer. They can supply you with a chart that has percentages , temperature and humidity. Ideally all the laminations are done in one shot. It is seldom possible to do so. The next best is to laminate on resin that is still green. If not is will require grinding and the bond will be secondary which is weaker.

[jfblouin]

Thanks for answer

I use polystere resin for my hull but I understand that vinylestere resin is better for secondary bond. Is it true?

I plan to use vinylestere for final wraping of the external collar (see my design at http://boatdesign.net/forums/showthread.php?t=5903 ) because I can't do it in the first step.

Also I want to use Epoxy resin for my bulkhead for it strengh and good secondary bond. Does I'm in the right direction?

I dont use Epoxy for collar because I want to brush or spray Gel Coat on the hull and I understand that the gel coat can't be put over Epoxy.

[nassaw]

Polyester is still not so expensive that small test can be done to check reaction with your climatic area and give you 1st hand experience with type of resin you choose. Being close to your area. My key for Stypol poly is 15cc MEKP per 1/2 gallon will produce 45 minute pot life and a 75 minuite gel after lay-up @ 75 deg F.
25cc MEKP per 1/2 gallon will produce 20 minutes pot and 35 min. gel after lay-up @ 75 deg F. These times can be changed with simple things like MEKP temperature storage. If the resin should kick while brushing. Don't try to continue. Drop the bucket and grab a fresh batch to finish the skin. My advice is to use a no wax resin so if you cant complete the schedule all you need to do is wash with acetone to resoften and start over. You can add wax to the last skin for the proper cure. Waxsol is the product I use.