Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Fiberglass Top Repairs - How To's?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Greg72, Nov 5, 2001.

  1. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

    Joined:
    Mar 5, 2001
    Posts:
    15,683
    Likes Received:
    1,392
    Location:
    642 Days to BB2018
    Fiberglass Top Repairs - How To\'s?

    Like most people who have an older K5, I've got a fiberglass top with a bunch of small and not-so-small cracks in it. I am not sure what the best way will be to "correctly" fix these.

    Obviously, I can get some fiberglass patch and resin and lay-up a few pieces of glass on top of the crack, but that seems like a very "superficial repair, and that it will likely crack again....since I really haven't added any strength to it.

    I want to really do a nice job and "restore" the top, not just patch it to keep the water out. Should I be 'feathering out" the area around the crack so that I can use larger pieces of fiberglass for the repair?

    Are there stronger types of resins than others that would be better for this type of repair?

    Just looking for help from anyone who has experience with fiberglassing, or these type of structural/cosmetic repairs.

    -Greg72
     
  2. 1986Blazer

    1986Blazer 1/2 ton status

    Joined:
    Jun 13, 2001
    Posts:
    511
    Likes Received:
    0
    Location:
    Key West, FL - Southernmost Point
    Re: Fiberglass Top Repairs - How To\'s?

    I do some fiberglass repair work down here in Key West. My hardtop also has small cracks but they are mostly surface cracks and do not affect the structural qualities of the top. Basic fiberglass resin does not work well without some type of glass cloth used with it. There are many different types out there, unidirectional weave, bidirectional weave, chop cloth and several others. Your best bet is to go with Epoxy Resin and Fiberglass Cloth. Epoxy Resin is 5 times stronger than basic Poly Resin. But Epoxy Resin can be dangerous and is nasty stuff. Make sure you have a respirator or face mask. The Epoxy in a liquid state is nasty and can cause all sorts of reactions. The cured resin can cause problems if you sand it and inhale the dust. Just be careful, but all danger aside, Epoxy is the strongest resin available. If you have a major structural crack, simply filling it or laying glass on top is worthless. You must repair cracks and holes with a 12:1 patch. If you have a 1/4 inch thick fiberglass you need to use a 3 inch patch (12:1 ratio). The hole or crack that is there must be cut out until you reach solid and and structurally sound fiberglass. Example, you have a 4 inch long crack, you, must cut the crack out thereby creating a much larger hole. You then have to sand and fair it down. Once that is done, you have to lay at least four layers of fiberglass cloth in progressively larger pieces. The smallest piece goes down first. Once that is all done, you need to use what is often called Cabocell filler and resin to create the final layer. The resulting patch will be Stronger than the original. There are alot of other steps but that is the highlights of the repair. If you ignore this and do it with just a few simple "patches" remember this. You MUST make sure the area is absolutely clean. If there is any wax or oil residue the resin WILL NOT adhere and it will delaminate in a few day or weeks. Boat shops sell the required products but make sure you get a small can of fiberglass cleaner and make sure it says it will remove wax residue. If you need more info, let me know.

    <a target="_blank" href=http://www.geocities.com/keywestk5/KeyWestK5.html>http://www.geocities.com/keywestk5/KeyWestK5.html</a>
    So I says to him, I said, "get your own monkey."
    1986 K5, 350 GM Crate, 700R4, NP208
     
  3. 1986Blazer

    1986Blazer 1/2 ton status

    Joined:
    Jun 13, 2001
    Posts:
    511
    Likes Received:
    0
    Location:
    Key West, FL - Southernmost Point
    Re: Fiberglass Top Repairs - How To\'s?

    Oh yea......make sure you always wear long sleeves and jeans. If you start sanding fiberglass and get it on your bare skin, you will itch for hours. It really is not bad it just makes you itch. Also, when handling resins, USE GLOVES. Never use bare skin. Most hardware stores sell gloves. Buy a box of disposable VINYL gloves. They seem to work better for me when handling resins. Saftey glasses are a must, you do not want resin dust in your eyes. And lastly, if you go about this and need to cut fiberglass, you MUST us carbide tools. Fiberglass is actually harder than steel. You can cut steel with most drill bits, saw blades or cutting wheels. You try those same tools with fiberglass and they will self destruct in a few seconds. Then you are left with a useless blade and will go through a bit or blade every few minutes. Get Carbide - there is no other way to effectively cut and shape fiberglass. Also, if you go about "feathering" or fairing the crack site, you will need a rotary sander with a carbide sanding disc.

    <a target="_blank" href=http://www.geocities.com/keywestk5/KeyWestK5.html>http://www.geocities.com/keywestk5/KeyWestK5.html</a>
    So I says to him, I said, "get your own monkey."
    1986 K5, 350 GM Crate, 700R4, NP208
     
  4. bobsurf

    bobsurf 1/2 ton status

    Joined:
    Jun 26, 2001
    Posts:
    410
    Likes Received:
    0
    Location:
    San Marcos, CA
    Re: Fiberglass Top Repairs - How To\'s?

    My buddy used Kitty Hair to patch lots of small holes in his top. Standard method of cleaning the hole up a bit, and tapering out. It seemed to work pretty well, but it dries green, requiring a paint job. FYI, it also did a decent number on my surfboard.

    Newbie, 73 Blazer project
     
  5. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

    Joined:
    Mar 5, 2001
    Posts:
    15,683
    Likes Received:
    1,392
    Location:
    642 Days to BB2018
    Re: Fiberglass Top Repairs - How To\'s?

    Chris (1986Blazer),

    THANKS! That is some good info....I suspected that I would have to enlarge the area to get an effective and strong patch. It's a little discouraging to hear that the best materials to use are going to require all that protective gear, and carbide tools....Oh well, if that's what it takes, I'll do it. [​IMG]

    I may take a few photos of the "trouble spots" and post them in my Webshots page. It would be nice to have you and anyone else help me evaluate the damage and confirm what the correct "technique" will be to repair them.

    As I mentioned before, many cracks look like surface-type cracks, so the majority of the repairs should be simple. There are a couple of spots that look a little "scarier", and those are the one's I'll probably show you guys with pics. I'll save them to fix last, so that I'll be more confident when the time comes.

    Another question: It seems that the K5 tops (I can only speak for the 1st Gen style) have a textured paint on them....then a "yellow" undercoat and finally a white base. I'm guessing that the yellow coat is some sort of "scratch filler" and the bottommost white layer is the original fiberglass/resin? It seems that for any repair work I do, I will need to bond to that white layer. Does anyone know what TYPE of resin and fiberglass the factory used on these tops?

    -Greg72
     
  6. 1986Blazer

    1986Blazer 1/2 ton status

    Joined:
    Jun 13, 2001
    Posts:
    511
    Likes Received:
    0
    Location:
    Key West, FL - Southernmost Point
    Re: Fiberglass Top Repairs - How To\'s?

    I have not cross sectioned one of the K5 tops but regardless of the different layers, you can use any type of fiberglass resin to fix the section, it does not have to be the same type as the one used to make the top. Epoxy is the strongest and the best but you can get away with basic Poly Resin - Home Depot sells it along with the some fiberglass cloths. Most boats are made out of Poly Resins. Be carefull though, the type of cloth most stores sell is called Woven Roven and is a thick and hard to use cloth. Woven Roven us used primarily to build up thick layers of fiberglass when building boat hulls. It is strong but it is not best for repairs unless you do not mind a woven pattern on the final coat. Look for bidirectional fiberglass cloth - you can get it at marine shops. If is very fine patterned and costs a little more. You can go with Polyester Resin, it is not as nasty as Epoxy and does not cause reaction on skin. Since you are not fixing a boat hull, Poly Resin will work great! Also, if you cut out the crack and the cut does not go all the way through the top, a backing will be required. I can get you more information about this later. There is also an easy way to make the top much stronger so you can carry several hundred pounds more that you can normally. It is easy but a little more technical than a simple repair. I can give more details later if you want.

    <a target="_blank" href=http://www.geocities.com/keywestk5/KeyWestK5.html>http://www.geocities.com/keywestk5/KeyWestK5.html</a>
    So I says to him, I said, "get your own monkey."
    1986 K5, 350 GM Crate, 700R4, NP208
     
  7. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

    Joined:
    Mar 5, 2001
    Posts:
    15,683
    Likes Received:
    1,392
    Location:
    642 Days to BB2018
    Re: Fiberglass Top Repairs - How To\'s?

    YES! Please keep that info coming....!

    There's a boat shop down the street from me, so I might take a ride down there later on and see if I can get the materials you are talking about.

    Thanks again for the help.

    -Greg72
     

Share This Page