Fiberglas Pro Help??

[Clois Harlan]

Hypotheically, if a person wanted to extend a fiberglass panel what would be the best way to go about it?


Assuming a 1/4" thick panel that you need to extend the edge a maximum of 1": would it be best to move over from the edge and cut and splice in an area or is there a BEST way to extend an the edge an inch?

I know some will think the answer is to purchase another panel but that is not an option....no longer available.

Thanks,

Clois Harlan

[saltshaker]

In the boating ind when we would repair a large hole Ina hull or deck we would glue a piece of styrafoam with a hot glue gun to the back side and glass over it. To remove the styrafoam just dissolve with some gas....works every time .
Jon

[alfy65]

I remolded my front flares by building layers of plywood strip, plaster of paris and waxing after 24 hours of drying time.I extended the new glass in layers back about 3" after grinding off gelcote and formed the flares to about 3/16".Stripped off the forms and put two layers of glass under the flares.Used the styra trick to make new doors and inner panels but left the foam in place..Seemed to work fine..I put some pics in my gallery..

[Clois Harlan]

Thanks, I will try to extend the edge on a piece of scrap flat FG this weekend. Thanks guys for the suggestions. The styrofoam sounds interesting and quick for the back side and then extend it as alfy said. I will give them a try.

[PaulProe]

Clois,
When I worked on my body, I learned to extend or patch a hole, the best joint was a "scarf joint" where it tapered back, on both sides, on a ratio of about 12:1 That means your edge would be tapered to a knife edge, with the sharpest point being the middle of the material. If the panel is 1/4" thick, then both sides would be tapered back about 12/8 or 1 1/2". Then the layers are built up individually, to the new edge that you want and extending the glass in subsequent layers over the old edge. Ideally, you want multiple layers of glass layed on top of one another and gently overlapping each other as they climb the taper of the scarf joint.

This is a good link to Glass/Composite repair on the Fiberglast site

if done this way, the joint is as strong as the original material. Make sure you properly identify the material you are patching: is it polyester resin, vinylester resin or epoxy and use the proper material for patching it.

Fiberglast is a good source of materials, in case you weren't aware

Paul

[Ant]

You need to grind a wedge on the front side going back approx 2", the edge needs to be sharp as no butt glueing is recommended as there is no strength or surface area.
The wedge or scarf in boats is 1/2" per ply, if I am bonding a new flare on my cobra I do about a 3" taper scarf going right down through the gelcoat, I try and avoid bonding directly to gelcoat as sometimes it can be really thick and there is no strength in coloured resin, so I need to see glass fibres!

Polyester resin relies on the abraded area and fibres in it for strength, it is not a great glue like epoxy which is used for structural areas etc. even with epoxy I would use the same scarfing area technique, my front guard flares have been remade in epoxy due to a damage repair and you cant lay polyester over epoxy.

[Clois Harlan]

Great information guys and I really appreciate your help. I wouldn't have done the knife edge but it makes sense. The area in question had been cobbled up by the person that made the piece e.g.: left side is almost 1/2" thick and the right side is less than 1/4" thick. Both sides are short from 1/2" to over 1" on the thicker side. Very poor attention to detail by this individual but everything can be properly fixed given time and the proper treatment of the area. I really appreciate everyone’s input because I only want to do this once.

If I think about it I may take pictures and post them for others to reference. This site has always been a huge source of information for me so maybe I can give back to the next person that is faced with this dilemma.

[alfy65]

Oh yea...photos are always cool..good luck

[Wbulk]

Clois,
Newton's statement is right on:
"Polyester resin relies on the abraded area and fibres in it for strength, it is not a great glue like epoxy which is used for structural areas etc. even with epoxy I would use the same scarfing area technique, my front guard flares have been remade in epoxy due to a damage repair and you cant lay polyester over epoxy."

I would not use polyester for repair. Epoxy is far stonger.

And yes please post pictures. I am thinking of putting flares on my rear fenders.

Wayne

[Clois Harlan]

What product would you recommend Wayne?

EVERFIX??? http://www.defender.com/product.jsp?...36678&id=18636

[Wbulk]

That may work. I've used these guys.

http://www.uscomposites.com/epoxy.html

They are real helpful. (561) 588-1001

[Learjockey1]

Another really good boat repair and construction epoxy is the West System. They have the technology down to a science and you can get all the products, fillers, glass, different rate hardners, and info from any good Marine store like West Marine etc (not affiliated with West System)