Completely clueless

1708 has mat in it.
1700 does not.

The stuff with mat is far easier for newbies to use because it doesn't deform. That same ability to not deform can be a negative on compound curves. Very few compounds on this job..

I am using both types in my build.

The 1708 is a little harder to wet out and uses more resin. Wetting out glass requires making sure it is all translucent. When you wetout the stringers; you do it with a hotcoat and then you'll roll epoxy over the area to be glassed and lay down a single piece in the wetted area. And then wetout more from above.

1708 uses about 25 ounces of resin per square yard

Yeah....you need to keep enough struture to avoid the boat changing shape.

Also, take no shortcuts. Glassing over multiple stringers in one go is like chasing yourself.

 

1708 works fine with epoxy

 

Thanks again. Now I just need to figure total amount

 

1708 works fine with epoxy, but increases the cost (may double the amount of epoxy needed) and weight with no real benefits, might as well use a lower cost resin if CSM is included in laminate. Any of the typical resins will work for this project.

 

Yes. Other resins are fine. 1708 adds about 1/3rd to the resin budget. If you are real careful; 1700 is fine; just mark the center of each piece of fabric with a black sharpie to make sure you don't let the snake win...

I would NOT reuse the old stringers. The likelihood of starting off with some rot is not worth it.

 

After lots of math figure I need about 23 yards of cloth. How far would a gallon of resin get me?

 

"Cloth" is sort of a generic term, it doesn't describe the exact weight of the fabric, or even the style of fabric.

Woven and stitched fabrics use about their weight in resin, so you can add up the total weight of the glass and expect to use about the weight in resin. CSM will use about double it's weight in resin, this doesn't include what you waste, and being new to it you'll make some mistakes, so buy extra.

 

23 yards of 17 oz cloth is 3 gallons of resin
23x17/128

If the yardage is right; 3 gallons will be a tad short.

If you underuse resin; you will have dry, weak laminate.

I would not use polyester for this repair as it is not waterproof.

1708 will need 4.5 gallons... you can use 1700, but you cannot move it wet without great effort.

You can reduce your budget if you shorten the glass on the hull to inch overlaps; so say 2" on hull, 3", 4" versus 2,4,6

 

At one time it was my job to glass in stringers and frames with Fabmat, which was 24 oz woven roving with a 1-1/2 oz csm adhesived to the back. We always pre-coated wood and let it set-up before glassing, to eliminate dry spots and bubbles under the glass. The frames had stringers going through them, so the pre-cut piece to cover the frame had slots and flaps and holes to accommodate the stringers. It was impossible to get resin through a layer of fabmat from one side, so the standard procedure they showed me was to lay it out on a piece of cardboard, wet the mat side, peel it off the cardboard and lay it on the frame to finish wet out. That proved a royal pain as it would start falling apart, get all misshapen and looked bad in the end. The trick was to lay the dry glass in place over the frame and then folding back one side along the top of the frame, heavily wetting out the mat and folding that side back in place. I would do the other side the same way, and then wet out the whole piece from the top (the woven roving side) and then finished with the bubble buster rollers. That way enabled the glass to be perfectly wetted out while also being perfectly in place and looking very professional.

 

Nothing is waterproof, materials just have greater or lesser degrees of water resistance.

Polyester resin is sufficiently waterproof for virtually every application in a fiberglass boat build, or repair. This doesn't mean it meets the desired goal in every build or repair, just that not being waterproof enough is sort of an old wives tale. And like any other product, you need to pick a suitable version and then use it correctly, but in a stringer repair just about any polyester will work well enough.

If using epoxy, skip the 1708 and use 1700, the moving it around hassle is sort of a non issue, just wet it out in place, which is the normal method of using it.

 

The only reason I mention moving 1700 is impossible is he is a noob. If he got the idea he could; he'd waste materials.

The resin usage is much higher as I stated.

 

I don't mean to sound argumentative, I tend to get overly picky on how things are worded and explained, the reason is because in the future when someone googles boat repair and reads this thread, or any thread that comes up, they read "polyester isn't waterproof", "only use epoxy when doing repairs" or "use 1708 with epoxy" or something similar, now in their mind that becomes fact and is repeated in every conversation and thread they participate in in the future. I've battled this for more than a decade on various forums that involve repairing composites.

While at times, and used in the correct context, these things can be correct, but as a general rule it's not the case.

 

As a noob I appreciate everyone's help. I logged into fiberglassSite.com and carted 30 yards of 1708 5 gallons of poly resin and a 6" roller. Quite a chunk of change. Just curious if anyone knows of a cheaper place that would stock these things, also if there's something else that would be needed.

 

You should be able to guess alot of the basics mix pots gloves ect

cab-o-sil is added to thicken the resin. Especially useful if the bonding surface is textured.
The squeeze bottle has mekp in bottom squeeze some into its upper measuring cup. The medicine dropper is useful for small batches

 

Just price out WestSystem epoxy for the job and you'll feel better about the cost of polyester.

If you're willing to put that much money, and work, into polyester, you may want to consider epoxy.
Just not WestSystem... unless money is not an issue.
WestSystem is nice to work with and an excellent product.