Epoxy resins question

[Joeytier]

I have an old 14 foot fiberglass canoe with a thru tear about 7 or 8 inches long [sorry, no pictures at this time]. I have never done a repair of this nature, but it seems as though all I will need is fiberglass cloth and marine grade epoxy resin, with a filler for the top layer. What weight of cloth would you reccomend for the repair? This will be a lake canoe, and will not be facing much abuse from rocks. Are they any specific brands of epoxy resin or filler you would reccomend? Thanks in advance.

[Cosmos]

I have an old 14 foot fiberglass canoe with a thru tear about 7 or 8 inches long [sorry, no pictures at this time]. I have never done a repair of this nature, but it seems as though all I will need is fiberglass cloth and marine grade epoxy resin, with a filler for the top layer. What weight of cloth would you reccomend for the repair? This will be a lake canoe, and will not be facing much abuse from rocks. Are they any specific brands of epoxy resin or filler you would reccomend? Thanks in advance.

 

this is best thing you can get, solid as a rock:

http://www.canadiantire.ca/AST/browse/4/Auto/AutoRepairAccessories/SpecialtyRepair/PRD~0475824P/Bondo+Resin+Repair+Kit%2C+1+L.jsp?locale=en

[whiskywizard]

The canoe will have been constructed of polyester resin and fibreglass. The challenge now is getting a good bond to the fully cured canoe. You'll get the best bond with epoxy. My preference is West System epoxy, but others are good too, like Mas Epoxy. Any boating/marine supply store will carry one or both and even in kits that include some cloth, mixing pot and sticks.

[krixxer]

it's all in the prep!!!

 

Take some 320 and knock down all the gloss. Around two inches around the tear inside and out. Use a DA if you have one. Follow it up with a few heavy strokes of 120 to give it tooth.

 

Alcohol, acetone, MEK or some other good clean solvent to degrease and you are now ready to apply the glass.

 

Don't work in direct sunlight and get a fan to blow at your back to keep the fumes down. (I presume you don't have a respirator)

Edited April 20, 2012 by krixxer

[F7Firecat]

The canoe is made out of poly ester resin not epoxy resin.

 

A total repair laminate of two stages (layers)of 4ounces each would be plenty

 

I dont know what weight of chopped strand mat you can buy at stores like canadian tire, but if it is one ounce you will need approximately 8 layers of the 1 ounce mat. You may be able to get some boat cloth or woven roving, and you can put that in the centre of the laminate.

 

If you start at the canoe substrate go 2 mat, 1 boat cloth, 2 mat let cure, sand imperfections and repeat once again. If you have no boat cloth or woven roving just go with the chopped strand mat it will still be very strong.

 

Scuff the repair area very good, the rougher the better get all the gloss off, going at least 3 inches away from the crack, grind down the crack smooth, you can mix some resin with talc powder and make a putty and putty the crack let cure and sand smooth then apply the glass. This will prevent any air bubbles in the crack area.

 

All you need is a paint brush and dab the fiberglass and ensure to get all the air bubbles out. Keep it out of the sun as mentioned as it could bubble during the curing process.

 

Dont forget to add the hardener to the resin, its most important part, if you screw up at least it will go hard, and you can sand it start over again.

 

Once your done, lightly sand it find some matching paint and paint the area, if you want it to match.

 

I live in Caledonia and have everything you need, if your close by we could hook up, if not any fiberglass supply place would have it. Composites Canada in Mississauga has everything you need if your in the GTA.

 

Bryan

[SirCranksalot]

I've done several repairs on an old canoe. I just got the kit from C Tire with cloth and all. I may have had to buy extra cloth but it was nothing special---just what was on the shelf at C Tire. It seemed to work well for an old canoe. If it was a spiffy new canoe that I'd just knocked a hole in O might have been a bit more careful in my selections.

I have added skid plates to my kevlar canoe and for that I used the West system epoxy, which is a better grade than C. Tire. I think I used C. Tire cloth with that.

[Dabluz]

Do not buy automotive type fiberglass. Yes....canoes are made from that cheap stuff but they have to be painted with an epoxy paint to make sure that the fiberglass does not come in contact with water because polyester resin does absorb water. It is not made for constant immersion in water.

 

Buy epoxy resin. On top of that, with epoxy resin, you have more time to work with the stuff because it takes about 30 minutes for this stuff to get hard. Epoxy resin has no trouble sticking to polyester resin and is much stronger.

 

Depending on the tear, if there is a hole or not, the width of the tear I would use a thicker cloth. If it's just a crack, a very thin cloth will do fine. You could use a thicker cloth for the inside of the canoe and a very thin cloth on the exterior in order to get a nicer appearance.

 

Epoxy resin is expensive but from what I can see, you won't need very much.

[Freshtrax]

Just use a poly resin and cloth from crappy tire. Iit does not have to be the prettiest thing for an old canoe. I've got me that has a few repairs that have been there for years and I'm hardon canoes. I will post a pic. In a bit.

[F7Firecat]

Polyester resin does not like water.......your kidding right???? I wonder what Ranger boats are made of?

 

If the mat is left unsaturated and exposed to water or chemical it will act as a wick and suck the moisture into the laminate. Its all in the quality of the job you do not the resin.

 

I just hope all the FRP tanks I have lined with fiberglass dont start to fall apart.......

 

Ive used thousands of gallons of fiberglass resins and epoxy resin, never had one that wont resist water and btw a canoe would not be considered immersion service.

Edited April 21, 2012 by F7Firecat