fiberglass canoe construction

Hi, I’m looking to build a 14' river canoe out of fiberglass with this mold I’ve recently acquired. The mold is a half mold in which the fiberglass would be laid on the inside (female mold) the two halves once produced must then be attached together.
As I’ve never built a fiberglass canoe before I have a few questions about it
- My biggest question is how many layers of fiberglass should I lay and what types of fiberglass should I use to build a sturdy yet relatively light weight
- As far as supports / reinforcements I’m curious as to what kind of materials are needed if they are needed.

If anyone has ever built a canoe with a halve mold any information or advice would be greatly appreciated.
Thank you

 

first I think we need a photo of the mould to see what type of canoe it is ..certainly polyester resin will be much cheaper but how thick depends on how strong you need it and that dependent on your use ....you could build it thin and then add extra layers to the inside if you feel its too weak.....photo ..no need to host them just go advanced and add as an attachment ...click the paper clip symbol.......

 

Are you sure they are half molds and the hull shell is bonded down the centerline or is it a mold that's designed to be used, clamped together and the hull shell popped out whole, by separating the halves?

I you want a heavy canoe, use polyester. If you want lighter use vinylester, if you want really light then consider epoxy.

 

heres some pictures









from what i understand you build one half, then take it out and build the other. then im supposed to attach the two some how.

 

I can see if there were a pair of these it would be almost impossibe to glass into the for and aft extreems..so it looks like glass it with a trun down along the entre line ...getting the thickness right particulary at front and rear ... Then clamp the two together ..wet resin along the join line then resin and glass inside . easy . Then grind off the surplus. Trim top edge with timber...cross seats etc ..looks like a technical school facility to me ....

 

interesting , hope you take some photos along the way i would like to see them.
thx

 

fiberglass

I’m going to use fiberglass for its construction. I’ve seen some things online where the builders say to layer woven fiberglass cloth and fiberglass mat one after the other. However I’ve yet to see any information as to how many layers of each or whether or not this is a good idea. I was also wondering if there are any recommendations toward what type of (s-glass or e-glass) fiberglass and how to layer the woven cloth.

 

Building one half and then the other and marrying the 2 is really a pain. I use to produce 100's of 15' and 17' fiberglass canoes.. Using a 1 piece hull mold with a split in the stern of the mold with a flange

For Layup just use one layer of 1 1/2 ounce matt and one layer of 18 oz woven roving. If a stiffner is needed to min oil canning from a flat bottom canoe. Use Microballoons or thin core mat on floor of canoe. OR Glass in a 3/4 " 1/2 round into floor. This works too.

If you use more than one layer of mat and roving Your canoe will weigh a Ton

 

greetings shawn here

im no exspert, but i know just enoughf for trouble

i have a great book on doing white water boats, by charles wallbridge
discusses great detail on layup, stress risers, and differnt resins and weaves.

also id avoid mat for this small a boat and just use cloth and roving- mat cheap& is stiff but real heavy

other advice is possable? ends may need a little extra cloth layers due to aditional stress, and bottom in a canoe can be real flat, may need rib- but watch stress riser- the book talkes about spaceing such distances multiple layers. good luck

 

its been awile but i just thought about this site and that i never made a final update of progress, as far as the canoe goes its finished i used one layer of woven roving and a layer of fiberglass mat to construct the two halves.
after that i used a saw and a belt sander to prepare the edges where the two halves meet. we then taped the tow halves together so that we could easily use fiberglass tape down the center. i then used pieces of fiberglass matt that i coated with epoxy and then stuffed into the seam for the front and back.
next we used unidirectional tape to act as ribs in the boat, we did nine ribs with a closer concentration toward the center of the boat. we later added two layers of very thin fiberglass cloth tho strengthen the floor of the boat... the unidirectional ribs really help with strengthening up the boat. we then made bulkheads in the bow and stern to aid with overall structure the foam was covered with some leftover woven roving and thin cloth. ( had i had known what i was getting into i could have made the bulkheads more visually pleasing but by the then it was too late.
the bottom of the boat we put a strip of 6" wide Kevlar tape the whole length and then we put a wider piece of thin cloth over top of that.
the hardest part was fitting the wooden edges to the boat (the inside pieces that is the outside ones we thin and easy to bend) with the curves that it has and with no steamer to bend the wood properly. eventually i was able to get it to look half decent after two time it broke under stress. also the one edge didnt quiet meet up at the tip ( bad measurement on my part) i fixed that by mixing epoxy and sawdust that i then plugged the gap with. to cover my mistakes we added the end plates. then we added screws along the edge to help the epoxy hold on the edge.
the final touches were the home made yolk and then a coat of epoxy on everything once it was smoothed and the rough spots were sanded out.

 

Great job! Make sure you protect your epoxy with some UV inhibiter. Are you planning to paint it at all?

UV light degrades epoxy. If left uncover, your canoe will age and start falling apart if left exposed. Paint provides the best coverage, but will hide your handy work. The translucent appearance of your canoe has an interesting look. You can use a varnish with UV inhibitors. These might throw an amber cast on your project. There may be clear finishes with UV inhibitors. I am not familiar with them. Others might be able to suggest an alternative product.

 

yea i was planning on coating it with a layer of varnish that to protect the epoxy while maintaining the transparency. ive just havent had time so its in storage till i get the time to finish it

 

Rather than using woven roving use double bias its a much better glass and all the strands are working all the time where as woven roving just part of it i most cases is working for you !! The way the glass strands run makes a big differance to the ridgidity of what you are making !! and for the join its the only glass to use !!