1991 Prostar 190 hull repair

[mikeg205]

Clean work...how many layers in the plan? What will you be using to replace - the expanding stuff? Like this? http://www.evercoat.com/productDetail.aspx?pID=308 - or do you have something else in mind.

Well done by the way,

[bstewart0529]

We have 3 peices of glass in there now and we will have two more layers in the plan. Also we will put a layer or two on the outside as well. After speaking to the folks here that do a great deal of repairs and they said just to use the great stuff because I don't have a very big hole to fill. I will post more pictures later

[bstewart0529]

He are some more pictures. Looks very good. The edges sealed very well. Next weekend we should have the final coat aplied. Then gel coat the following weekend.

[bstewart0529]

One more

[MIskier]

I hope that you are planning on grinding the edges back on the outside before applying the layers to the outside. If you do not you wont get any strength from the patch.

[bstewart0529]

Oh yes. These were just pictures take to show how well it turned out. But thanks for the advice.

[mikeg205]

Originally Posted by MIskier

I hope that you are planning on grinding the edges back on the outside before applying the layers to the outside. If you do not you wont get any strength from the patch.

You mean feathering the edges so it's like \______/ (bottom is glass angle lines are gel) - more acute angle right? How much overlap is needed to make a really strong patch? - I'm a nube and and really interested on how to fix something like this even though I don't have too.

[MIskier]

Originally Posted by mikeg205

You mean feathering the edges so it's like \______/ (bottom is glass angle lines are gel) - more acute angle right? How much overlap is needed to make a really strong patch? - I'm a nube and and really interested on how to fix something like this even though I don't have too.

The angle all depends on who you ask, but a 12:1 bevel is ideal. Overlapping the existing gel after scuffing it by 2-3 inches and alternating between chopped strand and woven roving will result in the best repair for this type of situation.

If you're interested in marine composites I can recommend several book and have one on PDF. Feel free to PM me with your contact info and I will send it to you.

The books that I would recommend for a good basic primer: Fiberglass Boat Design and Construction published by the Society of Naval Architects and Marine Engineers.

More advanced topics: Introduction to composite materials

Hexcel Composites and SP High Modulus also have many great resources on their websites.

[TRBenj]

Originally Posted by MIskier

The angle all depends on who you ask, but a 12:1 bevel is ideal. Overlapping the existing gel after scuffing it by 2-3 inches and alternating between chopped strand and woven roving will result in the best repair for this type of situation.

That doesnt sound like the "best" advice to me. Agree on the 12:1 taper, but I would NOT suggest that its ok to lay new glass over the existing gel. Gel has no strength and should be ground off entirely in the damaged area, and new glass should only be laid over old glass. I also do not care for woven roving in a repair... its better used for initial layups where a quick buildup is required. A higher number of thinner layers will make for a stronger patch. I'd make my patch with more layers of cloth than anything else, and a few layers of chopped strand (mat) in there as well. Shoot for matching the original thickness, or going a touch thicker. The mat will help build it quickly and give strength in all directions. Each successive layer should be slightly larger than the one under it. Make sure you get the air bubbles out of the layup... a grooved roller helps a lot.

[mikeg205]

Here's a great video http://www.youtube.com/watch?v=SsoKAHU5xUw late to the thread but I believe points to MI's 12:1 ratio bevel. It has a cool solution to do the gel coat repair as well.