View Full Version : How do fix this? (Fiberglass)

03-27-2011, 09:28 PM
I need to repair the hinge pads on my motor lid. The wood that the lag screws go into has rotted out and no longer hold the hinges properly. I wanted to cut out the old wood and fiberglass in two blocks machined from alumium with stainess thread inserts so I can bolt the hatch on and not use the lag screws.

Although I have worked with fiberglass I've never done this type of repair. Any suggestions on materials I should be using. Should I start the repar from the underside or from the top?

Start from topside?



03-27-2011, 09:57 PM
How about a larger picture showing what it is this does?
I guess you could cut out the glass on the back side w/a dremel or other power tool, followed by the wood (plywood?).
I think I would just lay in some 1708 stitchmat until you reach the original thickness and through bolt the hinge.
The gel is easy to repair by cutting out the cracks w/a Dremel and ball end cutter, then fill w/some thickened colormatched gel.

03-27-2011, 11:38 PM
Hey guy a larger pic would help and from the looks of things there is a whole lot of dry chop going on there .

03-27-2011, 11:51 PM
Hey guy a larger pic would help and from the looks of things there is a whole lot of dry chop going on there .

exactly my thought!!

start grinding until the white is gone ,,pink is the sweet spot!!:wink:

04-14-2011, 09:23 AM
Sorry I don't have any pictures of the whole assembly but think of motor hatch with two hinges attached. The white gel side is where the hinges attach and when you lift up the motor lid it's what you see underneath. The unfinished side is where the foam cushion goes and then gets covered with a sun pad. Ok, I have to come clean now...it's not a Donzi. I had to sell my 22' to get something bigger. I've obtained a lot of good information here from reading other projects so that's why I still monitor the site.

Anyway, I used a multi-tool (awesome tool btw) to cut out the pockets shown on the unfinished side of the engine hatch. Pulled out the rotten plywood and will machine two aluminum blocks with stainless thread inserts so that I can bolt the hinges in place instead of using lags screws like the original design. They cannot be through bolted because the foam and sun pad will be covering the other side when everything is back together.

Here's a list of materials I think I need to order. Let me know if I missed anything or I should think of something else:

1. Epoxy glue to secure aluminum blocks to existing fiberglass surface that I dug the plywood out of.
2. 1708 Knit Fiberglass
3. 935 Epoxy Resin

The side I am working on will not have to be finished with paint or gel, hence the epoxy resin. I figured since it's a hinge pad the extra strength of epoxy will be good here. I plan to purchase everything from US Composites today, their prices seem very good. Anything I am missing?

04-14-2011, 10:25 AM
Anything I am missing?

Yes, plan on painting the epoxy layup. It doesn't like sunlight and will degrade quickly if not protected.
It's just a good thing to do. Looking at your picture, it's obvious sunlight gets there.

04-15-2011, 10:33 AM
I would recomend using Imron or Awlgrip because because jell is not very epoxy friendly (compatible )and if you can stay away from a chop back fabric when using Epoxy , like 1708 .