Deck lamination questions

[hyboats]

1 should I use tissue mat for deck
2 how about put some Q-cell (polyster resin mixed with small glass sphere) in corners ?
3 hatches , doors also need to laminate step by step (after one layer harden then laminate next layer)
Sorry this is my first time to make a boat, before this I only did some repairment work.

[Herman]

1. Not neccesarily. Tissue mat is for preventing print. If your resin system / working system is not giving you print, then it is a waste of energy. You could do a test...
Preventing print is about getting a good cure of the first layers, before you move to the next layers. Keep that in mind at all times.

2. I do not lie Q-Cell because of it's "runniness" and brittleness. However, it is a good idea to pre-fill sharp corners, to prevent line bubbles. I like to use aerosil or a product called stewathix for that. But you could also use some polyester bonding paste. I like to apply it just before laminating that area, so with a bubble buster I can squish the paste around a bit.

Remember to design for the material you plan to use, composites in this case. Composites like nice, round corners, and organic shapes. Sharp edges can create stress concentrations, and cracks as a result.

3. Why not? Although you can gradually build up the amount of layers to be laminated in 1 go. But for the first layer or 3, I would do one at the time. Again to prevent print and shrinkage.

[tinhorn]

I agree with Herman.

Microspheres are useful for displacing resin, which helps minimize shrinking and printthrough, but they make terrible putty. Cabosil (fumed silica) will make a putty that will hang on vertical surfaces. (I don't think I've ever used a mold, whether kit cars, airplane parts, or industrial parts, that had an inside edge sharp enough to require putty instead of 'glass.)

[CatBuilder]

This thread looks like a good opportunity to learn a few things. May I ask a few follow on questions?

What about mixtures, such 75% microspheres and 25% colloidal silica?

Also, is it wise to just use West 407 all over the boat to be doubly sure of water-resistant integrity instead of 409?

[Herman]

I have no idea on the west product numbers (although I once started at the West distributor in NL)

On mixtures, it is a gliding scale. use a 50% mixture, and the properties will ly in between.

I forgot to mention in my post to design for composites, I will add that to that post, for clarity's sake.

[tinhorn]

Originally Posted by CatBuilder

What about mixtures, such 75% microspheres and 25% colloidal silica?

For "filled" resin I'd dump in about 20% by volume (which equalled about 2% by weight) plastic microspheres. I've never used glass microspheres.

To make putty, my practice is to dump a bunch of Cabosil into a container of resin, stir it thoroughly, then either add more resin to thin it, or more Cabosil to thicken it. Not very precise, I know, but sometimes you want a soupy paste, sometimes you want paste like stale peanut butter. (I keep a sealed jug of putty on hand so I don't have to go through all the rigamarole when I need just a dab.)

[tunnels]

After you have gel coated the deck it is best to use a layer of 300gram csm p Matt . This needs to be well rolled out and resin rich but not to the point of resin running everywhere.
Tissue is basicly used as a back up to hold resin to achieve a little more thickness to your gelcoat and help to prevent glass print through !The only places tissue gets used these days is below the waterline on Launchs and in conjunction with Vinylester resin to help prevent Osmosis!!.

Q cells and the like are only for making sanding fillers suitable for hollows and the like that will be painted over later . Using it in any part of a deck during the glassing stage is not a good idea . It has little to no strenght what so ever its brittle and cracks very easly if its in a place that moves .Simply dont use it .
If you want a filler that you can make yourself the use Talc , aerosill, and micro fibres with your standard resin that you will be using . Proprotions for the mix you will have to determine for youself .
Talc is heavy so dont use to much , Aerosil is for thickening , microfibres is to hold it all together so it wont break and is easy to apply and trowl out !
NEVER USE Q CELLS !!OR MICRO SPHERES IN YOUR MIX .

If you are doing filling on the first layer of glass mix a little of the same coloured gel coat with you filler , it helps to hide the filler

Try a little exsperimenting for youself !
Mix q cells and resin , catalyze and pour into a shallow plastic container do the same with the others i have listed as well. Take carefull note of whats in each mix !!Lastly mix talc , aerosil and micro fibres all together but take carefull not of how much of each !!also check you gell times with each one !!
Then let each of the mixes go hard and then tip them out and do a hit and break test with a hammer and see what holds together and what shatters into millions of bits .
When you add anything to Resin to make fillers or slurrys etc etc it slows down the reaction so it is possible to use a faster catalyst ratio . there are other ways of speeding it up but it could cause more problems than it solves .
You need to learn so play a little and lern a lot doing it !!

[hyboats]

I am now doing the test, two pics GRP. one sand to 1200, another sand to 1800, both are polished same material.
Maybe 3months later I can get the result.

[tunnels]

Originally Posted by hyboats

I am now doing the test, two pics GRP. one sand to 1200, another sand to 1800, both are polished same material.
Maybe 3months later I can get the result.

Paint them a dark color and lay the samples directly in the sun and weather !!The dark color will speed up the process as it will get hotter in the sun