I posted a few weeks ago about redoing the interior hull of my boat. It is the “unfinished” splatter finish so not smooth gelcoat. There are some holes I plane to plug and then glass over, ranging from 1" in diameter to 2.5"
I’m trying to start buying all of the supplies I will need to do this job so I can spread the cost over a couple of months. Upon looking at fiberglass cloth, I find I am overwhelmed by what is available. There is standard cloth ranging from 3 oz - 40 oz and S2 cloth ranging from 4 oz - 8.9 oz. Can anyone provide some insight as to what type/weight cloth I should use?
Obviously I will be painting this after I lay it down but, should I consider some kind of “putty” like EZ-Fair to smooth it out some?
AND, should I use a polyester resin or an epoxy resin?
I posted a few weeks ago about redoing the interior hull of my boat. It is the “unfinished” splatter finish so not smooth gelcoat. There are some holes I plane to plug and then glass over, ranging from 1" in diameter to 2.5"
I’m trying to start buying all of the supplies I will need to do this job so I can spread the cost over a couple of months. Upon looking at fiberglass cloth, I find I am overwhelmed by what is available. There is standard cloth ranging from 3 oz - 40 oz and S2 cloth ranging from 4 oz - 8.9 oz. Can anyone provide some insight as to what type/weight cloth I should use?
Obviously I will be painting this after I lay it down but, should I consider some kind of “putty” like EZ-Fair to smooth it out some?
AND, should I use a polyester resin or an epoxy resin?
Thanks
“Apathy is the Glove into Which Evil Slips It’s Hand”, but really, who cares?
Once you use epoxy, you got to keep using it cause nothing else will stick to it.
quote:Once you use epoxy, you got to keep using it cause nothing else will stick to it.
I’m taking that to mean that I would have to use epoxy paint when I go to paint over it? So, should I use polyester resin or epoxy and just plan on using epoxy paint?
“Apathy is the Glove into Which Evil Slips It’s Hand”, but really, who cares?
If you’re filling holes I would look into fiber fill. It is mixed with resin/ hardner,and you can fill the hole with it using a putty knife. When dry it sands smooth, it should blend in well. You will need to guess how much you need, and watch the temperature for how much hardner to add. As for the mat, chop strand should be fine. Just grind a little gel coat down and cut a piece to fit ground section, so it flushes back up with the gel coat.
If you’re filling holes I would look into fiber fill. It is mixed with resin/ hardner,and you can fill the hole with it using a putty knife. When dry it sands smooth, it should blend in well. You will need to guess how much you need, and watch the temperature for how much hardner to add. As for the mat, chop strand should be fine. Just grind a little gel coat down and cut a piece to fit ground section, so it flushes back up with the gel coat.
3M also makes a good vinylester putty with fiber in it. It’s called 3M VE has a white and red label and mixes with BPO cream hardener. Then go over with mat glass as said by seaox. Then use the 3M putty again to fair in smooth.
quote:Once you use epoxy, you got to keep using it cause nothing else will stick to it.
I’m taking that to mean that I would have to use epoxy paint when I go to paint over it? So, should I use polyester resin or epoxy and just plan on using epoxy paint?
“Apathy is the Glove into Which Evil Slips It’s Hand”, but really, who cares?
You can only lay epoxy glass on epoxy glass. Poly or vinyl resin won’t stick to epoxy.
What Seaox and Carterlee97 said. The 3m putty stuff works good for fairing out.
For what you are doing, polyester resin and 1.5oz chopped strand mat is all you need.
If you were installing new keel/stringers or something structural, I’d consider epoxy. But, polyester is entirely adequate and will give lifetime service. Aside: you can generally go over epoxy resins with polyester. You just have to follow the distructions. Epoxies can leave a layer of amines on their surface when they cure - referred to as an amine ‘blush’. When you apply polyester with MEK-P on top of that surface, the amines will consume some or all of the MEK-P in the polyester that is against the face of the epoxy surface. Generally, you can take steps to remove the amine blush. Sometimes it is as simple as a water rinse. Sometimes, better to sand off and remove all sanding dust. But, it can certainly be done. The important thing is to find and read the instructions for the products you’re using. Further aside - it is called a blush because if you apply white gel coat over an amine lace surface it will turn the gel coat slightly pink = blush.
If all you’re doing is fixing holes and resurfacing the inner surfaces of the boat, 1.5oz CSM will do everything you need very well. If you have any questions about the strength and toughness of CSM, get a piece of window glass a few feet by a few feet and lay up a 1’x1’ flat panel. Use 3 layers of 1/5 oz CSM and then try to destroy it the next day. You wouldn’t want to use only CSM in laying up a hull. But, for what you’re talking about, it will be gracious plenty and easier to work with than the other materials.
Poly will stink up your whole neighborhood. Epoxy is scentless for the most part. Epoxy is usually much easier to measure out using the pumps. Getting the poly to mekp ratio can be difficult counting your drops. Too much and your working time is limited, not enough and it may never fully kick. I recommend epoxy all day.
Don’t count drops. When using more than a little tiny bit of poly, it is much much easier to spend the $5 and get a squeeze bottle. The top cup is graduated. Squeeze to fill to the desired level and pour. Takes all the guess work out.
Epoxy is almost twice the price.
Take your pick.
17’ Henry O Hornet w/ Johnson 88 spl
26’ Palmer Scott project hull
14’ Bentz-Craft w/ Yamaha 25
For the record, the holes are 1" - 2.5" in diameter and are cut through the decking (3/4" plywood) that has fiberglass on each side. So, if I put down a layer of fiberglass cloth on the bottom side, could I then use this Fiber Fill to fill in and then put a layer of fiberglass on top or could I just not put a layer on top and paint/non-skid it?
Thanks, I have done a little with fiberglass before but, it was in a johnboat that I wasn’t as concerned about appearance.
“Apathy is the Glove into Which Evil Slips It’s Hand”, but really, who cares?
It will be difficult to make anything solid if the sides of the 2.5" hole are straight. I’d do a little work on the hole to make it taper and cut a 3/4" plywood plug to fit. (You want the shape of the plug to carry any load that lands on top.) Then, as you suggest, sand, tack, and lay a layer or two of something on the bottom side of the hole. Let that setup. At the same time, coat the plywood plug with resin. Once that bottom layer of glass is set/hard, mix a little thickened resin and use it to press the tapered plug into place. If you don’t coat the plug with resin and allow it to setup before you place the plug, the dry porous wood will suck up the resin when you place the plug and you’ll end up with a dry joint. Then, you just need to rebuild the top side glass layer. Again, that should be tapered away from the hole. Lay in successive layers of CSM to match the diameter of the hole as you build up.
I’d use a wooden plug like the original coring because polyester resin (assuming you’re using polyester) continues to contract for a long time. (Monomer is converting to polymer = contraction. Most of it happens in the first 24-48 hrs. But, enough continues to happen over time that you can see it. Older fiberglass hulls can eventually look a little lumpy because of this.) You could end up with a depression where the hole was. I don’t know if or how much epoxy might continue to shrink and for how long. Using a plug would eliminate the resin shrinkage from the equation. Don’t forget to add a little wax to the last layer if you’re using poly.
You’ll want to build it to just slightly high. Let it harden for a few days then sand it in.
Take a look at the vids I linked previously. That guys does a good job of showing the basic approach to just the kind of repairs you’re making.
17’ Henry O Hornet w/ Johnson 88 spl
26’ Palmer Scott project hull
14’ Bentz-Craft w/ Yamaha 25
“Apathy is the Glove into Which Evil Slips It’s Hand”, but really, who cares?
Beg you’re pardner…
I wasn’t done yet. You never said you were concerned about appearance!!!
“Thanks, I have done a little with fiberglass before but, it was in a johnboat that I wasn’t as concerned about appearance.”
Pod say you always breaking things so if your worried about appearance, you should take it over to PalmerScotts house and axe him to do it…he’s pretty anal about fiberglass…so was Cracker Larry.
You can screw in some backer plates with sheet rock srews and fill the holes with cheap fiber glass filler…sand it and put the non skid down…or make a career out of it.
I like vinyl ester resin due to flexability/moderate price/low water absorption…epoxy…MEH. Good for sealing fish/tabletops/paper weights.