New fiberglassing

[elemental123]

Im a newbie at fiberglassing so I'm looking for some clear guidance.
According to Google to cover 18sq ft would take about 70oz resin. So if I'm mixing 32oz at a time. Should i wet the area for one length of cloth and then do the top coat over the cloth... and then move on to the next row with possibly a new batch of resin?
or should i wet the whole area, lay the cloth, use up whatever resin is left and then finish immediately with a new batch of resin?

 

[fallguy]

18 square feet is two square yards .. to require 70 ounces of resin means at 1:1 ratio 70 ounces or cloth or 35 ounces in the stack

generally; this seems off

I prefer wetting the substrate unless the sides are vertical. I use about 40% of the needed amount for the cloth.

I recommend you tell us the cloth for better advice.

If you are asking about weave filling; this is generally done wet on green and not wet on wet.

 

[elemental123]

the cloth I'm using is 1.5oz chopped strand

 

[fallguy]

the cloth I'm using is 1.5oz chopped strand

How many layers do you plan?

csm weight is per square foot, so you are at 27 ounces for 1:1 resin ratio per layer

The csm will probably fall apart on you if you roll it off a tube, but my preferred method is 40% down on the table or substrate and 60% over the top off a tube

Here this is about 12 ounces first. You would roll onto the table with say a 1/8” paint roller for adhesives, any heavier and you lose 4-8 ounces resins to the roller. Then roll the glass off a tube and onto the substrate and the rest over the top, but for this light fabric; it may be easier to wet it all tops down unless the substrate will require some.

How many layers then? 2?

You would lay out with squeegee or roll a second batch of resin onto the finished and fin rolled first piece.

The resin system?

 

[elemental123]

In planning on doing two layers of cloth.
The resin is dcpd resin with mekp hardener.

 

[ondarvr]

fallguy likes the tube method, it is rarely used in the real world though. Not that it doesn’t work, it's just extra work to get to the same place, and can get messy.

CSM needs about double its weight in resin, plus the amount that may soak into the substrate and the fuzzy roller.

How you do it and how much you do at one time depends on the size and shape of the what you're doing. A big flat area goes quick, add some contours and a radius or two and you need to really scale back and adjust the area to meet your skill level.

I pour the resin on the surface, move it around quickly, lay the glass down, apply more resin and roll it out quickly. After decades of doing it you get quick, on your first try stick with a very small area until you get the feel for it.

And CSM is not cloth, cloth is a completely different type of fabric, still glass, but very different.

 

[kapnD]

Would be helpful to know what it is that you intend to fiberglass.
CSM has specific uses, but is not anywhere near as strong as a woven cloth.

 

[wet feet]

I think all the experienced laminators I know would use their experience to mix half a bucket full of resin and do the job in about 20 minutes.A novice will be a long way from having that level of confidence or speed.We don't know what kind of surface is being covered and that can make a difference.You can also expect to lose some of the mix in loading the tools with resin.The notional laminator I described would very likely use a lambswool roller to transfer resin and it would probably retain 120 grammes of resin at the end of the job and if a brush is used to get the mat to conform,then that will soak up some too.If you were to try pre-laminating the whole piece before applying it,you would very likely have it fall apart on the transfer to the intended location due to inexperience.Our experienced laminator would avoid this by just applying as much resin as he thought would be a good stating point and put the wet side to the job,before rolling it out and applying a bit more resin where necessary,then consolidating with a metal roller.A novice is better off dividing the mat into more manageable section and adding it piece by piece.I do have a personal preference for tearing the mat into sections,rather than cutting it as the torn edges are easier to blend into a smoother surface,without a series of steps at the overlaps.If in doubt use several small mixes and several small pieces of mat.If you over estimate your speed you will quite likely wind up with a cup of resin getting rather warm and smelling nasty as it goes off in bulk.an old paint tin half full of water is useful for pouring resin into before this stage is reached.A bit of practice on something to get the feel of the process may be a good idea.