Delamination

[sguerrero]

Got my boat off the trailer and started to inspect the hull and found two small spots of delamination. They were hidden by the bunks on the trailer, so I missed them when I was looking the boat over before I bought it. They aren't that big a deal, I would have bought it anyway.

Rather than sanding it out and filling it, has anyone tried vacuum bagging? My brother is an airplane mechanic and the way they fix delamination on non critical components (Basically anything that isn't holding the wing on) is to drill into it, fill it with fiberglass resin, and then vacuum bag the area to draw the pieces back together and to distribute the resin throughout the cavity.

The spots that I am talking about are maybe 5" x 5", they start were the bunk of the trailer would rest against the hull and then go towards the centerline. They are about 3' and 4' from the transom.

Just wanting to get some thought on this. It sounds like a very simple solution and would really reduce the amount of work.

[Peter McMinn]

Vacuum bagging is an interesting fix for your delamination. Question: how will the rigid layers of glass be able to "suck in" to conformity? Do you plan on replacing the loose stuff with new fiber/gelcoat? Having read up a little on the process, this seems necessary.

It would be great if you could provide some pics of your project underway!

Found a description of v. bagging here: http://www.info-central.org/constructio ... ging.shtml

Going to try it on my rudder!

[sguerrero]

If I decide to go this route I will put it up on the forum so that people can check it out.

To answer your questions, the delamination is under the gelcoat, so there is no opening to the seperated pieces of fiberglass I guess you would call it a blister. Since they are so small 5" x 5", I was hoping to just drill a few access holes in the gelcoat (top of the blister) and use a syringe to get the resin into the cavity. I would use more than enough to coat the inside and then using the tape and bag that I can get from my brother draw the pieces together with a vacuum. This should also squeeze out any excess resin and create a uniform layer in the cavity. I can push down on the blister with my finger and have it contact the bottom layer, maybe 20 or 30 psi of pressure ( obviously just a guess), and I can generate 80 psi with my vacuum pump, so that should be plenty.

Ultimately what this does is eliminate me having to open the blister and then build it back up with new glass and resin. By getting the resin into the blister and bonding the two pieces back together it should stop it from spreading and return it to one piece again.

At least this is what I think will happen. That is what I am trying to have some one on here tell me. My brother seems to think this is a no brainer, but he usually can see both sides of the fiberglass he is working with, were in this instance I can't, because of the double haul design.

I guess the worst that could happen is I try it, it doesn't work and I have to cut it out and build it up like I would have anyway.

[captainseasick]

You should grind open the blister and clean the surface. Whatever caused the original fault should be removed. Gel-coat is no big deal to replace. Sometimes you have to be destructive to be creative! I would grind out every bit of damage, and renew it. In the long and short run, that is the easiest and surest method. If you are trying to repair laminate that has separated from core material, the syringe and fill method can be a good fix, but only after drilling lots of holes so that the material can be cleaned and dried, before injecting resin.

[sguerrero]

Thanks for the input. I did open it up and clean it out. I didn't get a lot of response so I figured it wasn't the greatest of ideas. Besides that I ultimately wanted to see the exstince of the damage and make sure I was getting it all so I don't have to revisit the area later.

I guess there is no substitute for a little elbow grease and taking your time to do something right the first time. I HATE THAT!