Some fiberglassing questions

[bluegrasslover]

Boy, it didn't take long to have a few questions. I've been searching all over the place for the past few days trying to find an answer to these questions with no luck. I've seen several videos about wetting out the glass and that seems pretty simple and straight forward but none of the videos I've seen have dealt with corners, etc. What I can't find is any information on how the cloth is managed at the ends and corners of the pirogue when glassing the entire hull. In other words, at the bow and stern you obviously have more fabric than surface so it has to go somewhere. I figure you have to cut it but what is the best pattern? If you just cut it so it meets then you have a weak point at the stems. Should it be cut so that each side flaps over the other? I assume that this is probably what you want to do but it seems that the point where the bottom meets the stems would not get proper coverage. Does anyone know of a video or pictures that might explain this? Or is it that since I've never done any fiberglassing that I don't realize that it's much easier to form it to fit the boat than I think?

The next question is about glassing the inside. I plan on doing the bottom and up 4" inches on the sides for the inside of the hull. Do you cover the ribs completely with the fabric or do you do each section separately with some of the fabric going up but not over the ribs?

These seem like simple questions (and probably obvious for you veterans) and I'm surprised I haven't found an answer searching around.

Thanks for your help,
Greg

 

[rpecot]

Greg,

You and I are in the same boat! I just started building the UJ pirogue and have the exact same glassing questions.

How long do you plan to build yours?

 

[Jimmy W]

Yes, cut it so that each side laps over to the other side. That will double it up at what is likely a high wear area anyway. Once that is cured, you can then add another small patch at the bottom if needed.

 

[bluegrasslover]

Awesome, Jimmy. Thanks for the reply.

I'm hoping to be done in the next few weeks. Definitely before the spring spawn! I've got a ways to go yet. I have my ribs glued up and stems cut. I've got the sides cut but I haven't put those together yet.

Greg

 

[bluegrasslover]

Oh, what about the inside? Cover the ribs or no?

Greg

 

[rpecot]

Doh! I wasn't clear. :? I meant what length will you make your boat? Not how long will it take! :lol:

And ditto the cover-the-ribs question. I'm thinking: no, but I'd like to hear other folks opinions.

 

[Jimmy W]

I haven't made a UJ pirogue with ribs, but I think that I have read not to cover the ribs. It would certainly be a lot easier to just put it between the ribs. Trying to cover inside with one piece going over the ribs would be a real pain.

 

[bluegrasslover]

Trying to cover inside with one piece going over the ribs would be a real pain.

That's exactly what I was thinking which is why I wasn't looking forward to it if I had to do it that way. Thanks again Jimmy.
Greg

 

[bluegrasslover]

I meant what length will you make your boat? Not how long will it take!

What you asked was exactly right. I was tired and misread the question. I'm going as long as possible with 2 sheets of ply. I'm not going to scarf like you did since it seems like a real pain. I'm going to do a butt joint but I am going to cut the ends at a 45 to help make the joint a little less visible.

Greg

 

[oldsparkey]

I glass in between the ribs running the glass up to the bottom edge (or close to it ) of the ribs , let the glass cure then go back and tape off the area with masking tape. Leave the area open that you want for a fillet and fillet where the glass meets the ribs. This makes sure the glass is covered at that junction , seals the area and rounds off the bottom of the ribs where they meet the boat.

That also covers any scratches made with the razor knife if you pressed down to hard when trimming the glass at said junction of the bottom and the ribs.

1. Don't trim the glass till it is almost cured or it will move on you.
2. Make sure you pull the tape used to outline the fillets before they completely cure or the tape will be part of the fillet. Usually around 30 minutes is a good time , you can tell when you start if the tape is going to make a sharp , clean edge when you pull it.

 

[oldsparkey]

I realize this is the canoe I made but to show what I was saying about taping the area to do the fillets . the top picture is with the tape layed down , the bottom picture is with the tape pulled and the fillets done.

 

[stickbow]

Covering the ribs: I think it depends on the number of ribs you have (Haven't built UJ's version). On the boat I'm working on, there are only three ribs, they're a kinda odd configuration (trying to make them look like "knees" to appear historically accurate), so I'm actually planning on glassing them as well as filleting the joints. That is if it ever gets warm and dry enough to work outside without a boat shed/workshop

Covering the outside: Either overlap as suggested or cut right on the keel, then run a tape strip along the whole keel. If you're painting the whole boat rather than letting the wood show through the epoxy, you can actually do both for optimal abrasion resistance and strength. That's been important on the kayaks I've built with all the trees, roots, and oyster bars I tend to cram them into/onto/over. You can get away with being more messy if you're going to fair & paint rather than varnish.

 

[bluegrasslover]

Thanks for the info. My plywood only has 1 pretty side so I've decided to paint the outside and leave the inside natural.