Realistic expectations when re-coring deck?

[jssailem]

They are using a foam roller. But note slowly and a single direction. The issue is air bubbles. You are just distributing the liquid resin.

I like the plastic squeegee. Very light pressure. You are just spreading the liquid you have poured onto the glass cloth. I use a chip brush to dab the resin into the cloth and the laminate roller to get out bubbles and excess resin.

Note this is with very light pressure. You are moving the resin not the cloth.

 

[thinwater]

A foam roller has no or limitied application working from the inside, or IMO, laying glass in general. Wet the glass with a squeegee, roller the air out with a ridged roller.

Not very light pressure with the squeegee. Angle it forward and press the resin in to some extent, after you get it spread. This is thick glass, and this is how you work it in without lifting the glass. No chip brush for this. Squeegee and ribbed roller. The brush is very inefficient for this process. Try not using it at all, except for finish, on your next project. Really.

Last time I did a ceiling, the chip brush was ONLY used to add a little resin when smoothing the last layer. Even them, the roller did 98% of the smoothing. Pressure is what you want, and a brush can't do that. Dabbing with a brush is only for places a roller won't reach (some inside corners), for 1-2 layers of thin finish cloth, or for projects too small to break out the roller. A brush is also much messier than a roller.

The ribs let the excess resin and bubbles rise, while pushing the cloth down. A brush doesn't do that.
rolling
There is no brush on this work table!
more rolling

 

[jssailem]

Thin
I can understand your favoring of rollers.
I do not understand the aversion to brushes. The company linked in post #42 "Fibre Glast" provides brushes in their "All-in-One Fiberglass Repair Kit"
All-In-One-Fiberglass-Repair-Kit

Quart Starter Kit Contents:​

• (1) ½-inch diameter x 3-inch wide Wire-Handle, Plastic Roller​
• (2) 1-inch Brushes​
• (2) 1-½-inch Brushes​
• (2) Squeegees​
• (4) Pair Latex Gloves​

There are many usable tools and my past experience has lead me to understand it is not the tool but the craftsman using the tool that defines the results.

Chip brushes have a place and an application in the preparation of wetted glass cloth. Choosing not to use a brush is entirely the purview of the craftsman, in my opinion.

 

[thinwater]

Thin
I can understand your favoring of rollers.
I do not understand the aversion to brushes. The company linked in post #42 "Fibre Glast" provides brushes in their "All-in-One Fiberglass Repair Kit"
All-In-One-Fiberglass-Repair-Kit

Quart Starter Kit Contents:​

• (1) ½-inch diameter x 3-inch wide Wire-Handle, Plastic Roller​
• (2) 1-inch Brushes​
• (2) 1-½-inch Brushes​
• (2) Squeegees​
• (4) Pair Latex Gloves​

There are many usable tools and my past experience has lead me to understand it is not the tool but the craftsman using the tool that defines the results.

Chip brushes have a place and an application in the preparation of wetted glass cloth. Choosing not to use a brush is entirely the purview of the craftsman, in my opinion.

I do use chip brushes, on practically every project. However, the last few times I worked overhead (and I have done this a number of time) I did not use a brush for any part of the 1708 wetting process. A squeegee and roller does a better job, faster, with less disturbance to the mat. I'm just trying to push people to learn more about using ribbed rollers.

Wetting finish cloth is different and a brush is better. But typically you do NOT fully wet the last layer, because there should be excess resin being forced up from deeper layers by the roller, and you will still use a roller to work it down. You do NOT want much excess resin on the surface; it can crack. A chip brush will be used near the end, to wet areas that are light on resin and smooth out the very edge. Shouldn't take much, just a few dips in the pot at most, and only a few strokes her and there.

I extended the transoms (cat) on my last boat by 3 feet. All of the main lamination was pour and riller work, with very, very little brush work. Potting and taping in the steps, the spatula and brush came out, of course. As you say, tools for jobs.

Small projects are different. I made a tiller-holder using only finish glass and a brush. No roller.

I did not say don't use a brush. I don't have an aversion to brushes... except when they are the wrong tool. I pointed out that he didn't use one in the video. Not the same as saying I hate brushes. I don't use a jig saw when a table saw is the right tool.

 

[Project_Mayhem]

I rebuilt part of my transom to get a bit more practice before diving into the deck. As you can see the area above the anchor locker has no liner and being an anchor locker it will not be seen. Multiple fittings have already started pulling into the lower skin so this must be taken care of before stepping the mast. Before I dive into this project I have two quick questions:

• How much "margin" or border should I leave on the inner skin for the new glass to adhere to?
• The distance between the two skins appears to only be 1/2". Should this be cored with balsa or plywood?

 

[dlochner]

I rebuilt part of my transom to get a bit more practice before diving into the deck. As you can see the area above the anchor locker has no liner and being an anchor locker it will not be seen. Multiple fittings have already started pulling into the lower skin so this must be taken care of before stepping the mast. Before I dive into this project I have two quick questions:

• How much "margin" or border should I leave on the inner skin for the new glass to adhere to?
• The distance between the two skins appears to only be 1/2". Should this be cored with balsa or plywood?

End grain balsa would be my choice, with extra laminate in the areas where fittings will be mounted. Or, small sections of plywood at the fittings and balsa on the rest. The problem with plywood is the grain. Epoxy works best when it can saturate the grain and bond with the wood. Plywood over has large areas of hard grain where the epoxy may not bond well.

I would leave an inch or two of full thickness glass and then a 12:1 taper This will provide a good bonding surface with sufficient area.

 

[Project_Mayhem]

Thanks Dave!

 

[Project_Mayhem]

Ok, one last question... Is there any harm in using the 1708 tape I already have instead of a large cloth?

 

[dlochner]

Probably not, except perhaps to your wallet. Tape may be more expensive per square foot than cloth. Another consideration is the edge of the tape. If the tape is serged, i.e., the edges of the tape are woven to prevent unravelling, then there will be little ridges in the lay up where the edges of the tape butt up against each other. The tape will need to be laid up with an overlap which increase the amount of tape you will use.

 

[jnorten]

I did mine in a few weekends. About a 2 square foot section forward of the anchor locker hatch. I did it from below, accessing it from within the anchor locker. I'm glad I did it, but I don't think my body has been the same since. Imagine belly-up, torso in the anchor locker, legs dangling out and into the air. For hours on end. My wife had to pull me out once or twice.

Joking aside, it's doable. Mine didn't need to be pretty on the underside as it was just in the locker. The boatyard wanted to gelcoat the inside of the locker, etc. for about $2k after removing/reinstalling the headstay, bow pulpit, etc. I did it for maybe $30 of marine plywood and a variety of West System stuff already on hand. Lots of labor though.

You can use multiple layers of cloth if your cloth seems thin. Google and read up on what's appropriate for this application. I don't think you can do too much. Smear a bit of epoxy on what's left of the underside after removing the rot. ***Wet out the fiberglass OUTSIDE of the boat and then just massage it into place. You won't get much dribble onto your face.

 

[Project_Mayhem]

I've got a pretty good idea on how to approach this especially after rebuilding my transom. Access isn't horrible in this boat. I plan on tarping off the bow and head area and laying down some foam to lay on. I'm wondering if a 1/4 gallon of resin will be enough. Roughly how many layers of 1708 should be applied? Original skin is about 1/8"

 

[dlochner]

I've got a pretty good idea on how to approach this especially after rebuilding my transom. Access isn't horrible in this boat. I plan on tarping off the bow and head area and laying down some foam to lay on. I'm wondering if a 1/4 gallon of resin will be enough. Roughly how many layers of 1708 should be applied? Original skin is about 1/8"

I can't directly answer your question, however, since you are doing a lot of fiberglass work, why don't you make up some sample coupons. Use 4x4 inch squares of 1708 and lay up multiple layers, say 4 layers, 6 layers, 8 layers. Once cured you can measure the thickness of the coupons.

As for the skin thickness, a little thicker is better than thinner. An ⅛" thick layer to match the original thickness and then one or two layers over the whole area including the scarf joint.

 

[Davidasailor26]

1708 should be about 0.042” per layer according to

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I haven’t tried laying up 1708 myself, but I’ve done 17oz fabric without mat and it was very close to the 0.035” in the table.

 

[thinwater]

1708 should be about 0.042” per layer according to

Home | WEST SYSTEM Epoxy

The home of WEST SYSTEM marine-grade epoxy resins and hardeners for boat building, boat repair, home repair, and restoration.

www.westsystem.com

I haven’t tried laying up 1708 myself, but I’ve done 17oz fabric without mat and it was very close to the 0.035” in the table.

I've used a lot of 1708, and that seems about right. This assumes you roll it firmly.