Clever Fiberglass Repair Tips with Boatworks Today

Clever solutions to tricky problems are best shared with our customers so you can get right to your repairs without the guesswork and pitfalls of trial and error. Count on Andy Miller to demonstrate this brilliant method of fiberglass repair that can translate into many solutions for hard to repair areas. Using 1708 fiberglass and our High Performance Epoxy Resin with some milled glass fibers added for super strong adhesion and strength, Andy creates a fiberglass “plate” to install behind the flange he has cut in the stringer. Using screws and some string, he pulls on the installed plate to keep the pressure on the thickened epoxy he has used to set the plate in place. Several more layers of graduated 1708 fiberglass pieces are then applied to the outside, creating a solid stringer wall that will allow Andy to do his next repair there in the way he was hoping to – minus a crooked, half-baked old repair. Tune in and see how Andy makes this Bertram repair like new again!

Holes and large repairs often leave big areas to fill again with fiberglass, and when you’re working on the inside of the hull, finding a way to clamp that repair can be a real challenge. Andy’s screw method is a great solution that starts with a thin lamination of fiberglass and is, once cured, in a great position to be a solid backer for the subsequent layers of fiberglass needed for strength in this important area of the boat.

Andy gives great instruction for tabbing in new glass pieces, making it look easy, and proving that with the right materials and a little video how-to, most anyone can succeed at complicated fiberglass repairs. Check out today’s video of the week with Boatworks Today!

Related Products

Clear Epoxy Kits

High Performance Epoxy Kits include resin, hardener, and mixing tools.

Milled Glass Fiber

Short fiberglass filaments ideal for creating fine fillets and filling gaps.

Biaxial Cloth

Biaxial fabric consists of two layers. “1708” indicates the weight of each layer.

32 responses to “Clever Fiberglass Repair Tips with Boatworks Today

  1. why use 1708 with epoxy? Wasting money using the CSM! Really should be using respirator with epoxy when sanding fresh cured and applying. You will be sensitized in no time. IMO, this is a PE or VE job, I wouldn’t waste my money on epoxy.

    1. Hi WEZ,
      Why use 1708 with epoxy? Because the two work very well together 🙂 The added CSM on the backside is not a waste at all. In fact the CSM acts much like a glue / bonding layer within the laminate ensuring that there is full saturation of the glass layers and that there will be no dry spots. Excess resin is then worked out with the trapped air leaving a lean laminate with a perfect resin to glass ratio.

      Regular CSM sold here in the US is held together using a styrene based binder which dissolves when it comes in contact with PE or VE (which are styrene based resins). This type of CSM does not work well with epoxy for that reason. There are some manufacturers that make CSM using a powder binder that does work perfectly fine with epoxy. This material will be labeled as Epoxy Compatible. As for the CSM that is used on the backside of 1708, that is all held together by stitching. There is no binder used (styrene or powder based) to inhibit the use of epoxy.

      As far as my choice to use epoxy for this rather than PE or VE, there are a number of reasons that factored into this decision. Given this repair was on a structural member of the hull I wanted to make sure that I had the absolute best secondary mechanical bond possible. Epoxy does that better than any other type of resin. That’s not my opinion, that’s fact 😉 Also this repair had the *potential* to be difficult in respect to getting each of the layers situated correctly and having enough time to work the air and excess resin out of the glass. Anticipating this, epoxy provides a much longer working time than PE or VE. Would have been a real bummer to get to layer 5 of the laminate only to have the resin start to gel from the heat buildup and not be able to finesse the excess air and resin.

      Could I have used PE or VE for this? Sure, but for what advantage? The cost difference of epoxy Vs PE or VE with the amount of material used for this repair is negligible.

      Hope this addresses some of your concerns!

      Thank you

  2. Excellent video. Does not leave any questions should I or shouldn’t I.
    I have used some of your products on a small job and never had a question of there use or quality, and easy mixing containers.

  3. Very nice video. I liked the extra touches like numbering your layers and leaving a hidden note for the future (I have done that with home repairs and wish the people who built my home 250 years ago had done the same).
    There may be other ways to do this repair as someone else mentioned (what a unique concept), but your epoxy fix was a more relevant choice in helping me with a repair I need to do and as a general reference (like using the plastic backer). Thanks!

  4. Why use 1708? Why not. Although CSM is not very strong in a laminate, it dose several things well, and is often on hand in most fiberglass shops. A laminates strength is one thing, but its toughness is another. A layer of 17 oz cloth alone may have the strength necessary, but it may not meet the required toughness. An example would be building a dingy. A foam composite laminate may only require one or two layers of 17 oz cloth, but in such an application using 1708 would give you the additional laminate thickness to make the structure tough enough to pull up on a beach full of rocks. In this repair example, he may have wanted the additional stiffness the CSM added and using 1708 is convenient to use. When you lay up multiple layers of 1708 the CSM help one layer bond to the next. As far as choosing epoxy, well this is a pretty small repair and the extra cost is not significant compared to the labor. Epoxy make far superior bonds to the existing structure than polyester ever could. So this was a good decision that would be wise if more “professionals” followed, in lieu of taking the easy or cheaper way out by using polyester resin. Polyester is not designed for post mold bonding type applications. Polyester resin only does a fair job when used as such, since is does not cross link to the cured existing laminate your trying to tie it into.

    As far as wearing a respirator, well we all make that mistake from time to time. It is quite accurate that sanding fresh laminate a few days old is definitely not good, as the laminate is not fully cured. This is not something you want in your lungs. The hardener is the dangerous component.

    All-in-all, fiberglass is an amazing product in many applications, and learning how to work with it certainly is a useful skill. This video was a pretty good example.

    1. I use epoxy all the time. For the right job….This is clearly a VE/PE job. I would be using 1708 with that resin. PE/VE is used extensively in post mold repair with success. I understand the properties of the 3 types. CSM wastes valuable epoxy resin(FYI, it’s expensive). CSMs uses are for bonding and fairing with a VE or PE resin, period. But….the new people getting into this do not. Clearly Andy is a novice and guiding new boat owners in a poor direction.

      1. We will just have to agree to disagree. The application of 1708 in the repair Andy did, was appropriate, and done in a professional manner. I’ve been doing fiberglass work for 40 years myself. One thing I’ve learned, is there are many ways to skin a cat. It’s simply not the case that you must do things one way for a good repair result.

        It’s too bad retail stores don’t commonly sell combimat variations such as 1708, 2408, and many others, as they are very useful products that I’m sure would help the novice build many useful parts. What you find commonly available in retail, often falls well short of the products “new people” might need for most projects. In this respect, Andy’s video is quite helpful to someone trying to learn about fiberglass. You can read all about the many advantages and disadvantages of all the fiberglass products, including CSM, all over many sites on the internet, including many pages posted by the makers of such products.

        Epoxy may be more expensive, not much in this case for such a small repair, but it has many advantages. I would hesitate to recommend vinyl ester resin to the novice, it’s not so fun to work with. It’s sometimes used in laminates where water resistance is important, but epoxy is much better here too. Vinyl ester would be chosen because of cost, and often is. Another reason to use vinyl ester is it can be formulated to handle heat well, like in wet exhaust products. Polyester is easy to work with when wetting out any cloth, but far inferior in every other respect to the other resins. It often gets used for all sorts of inappropriate applications. Even some pretty good boat builders use it in ways where epoxy would be far better. One such example is bonding plywood bulkheads to hulls. While this may work, sort of or for a time, epoxy performs much better. Polyester also stinks (smells bad) and for the novice working in his garage, this alone could be a reason to choose epoxy.

        I don’t use CSM on it’s own much these days, unless bonding layers of heavy woven mat, which is also not used so much these days. I do use CSM to make small parts that don’t require much strength, like a dorade box. I do use combimat all the time for reason I stated previously. In engineered products where weight is an issue, you won’t find much combi products or CSM.

        Other hot topics that I’m sure will ruffle feathers –

        Most combimat products like the many variations of 1708 are designed for any of the common resins, including epoxy. Check with your cloth manufacture. They wet out just fine, but then this is something you have to learn how to do not matter what resin you use. Polyester is easier in this respect.

        I have used CSM that had binders not designed for epoxy, and yes, it can be a pain to wet them out, but is possible. Why would you use CSM, well it does help bond layers of cloth and it builds thickness, without adding strength though. I would not make parts in CSM only, and use epoxy resin. This is just to finicky and is too much messing around.

        Another common misconception is you can’t put gel-coat over epoxy repairs. Not true. You do want a well cured epoxy repair. It should be washed with hot water and a scotch bright pad to remove amine blush, and then sanded. Gel-coat works just fine over epoxy in this way. I’ve done such repairs that are years, if not decade old, and have had no problems.

        Finally, I don’t see trashing Andy is very constructive just because he approaches a repair in a different way than you would. Just saying, and I’ll now leave it at that for the rest to discuss.

        Admittedly, my comments are just my experiences, and your mileage may differ. Good luck and have fun. Fiberglass is such an amazing technology and a skill that can be useful for so many things.

      2. A novice with over 20 years of experience and over a thousand projects under my belt without a single issue lol 😉

  5. The step by step is very helpful!!!
    Another reason to love total boat.

    First it’s the supplies mailed with the product
    ( measuring bucket, stir sticks, gloves) now this!!! Thanks 🙂

    Yes, please film a rolling and tipping video, I have a restoration Hull painting job coming up; this would be great!

    Thanks boat works!

  6. Were you layering the individual sheets while they where still wet? If so where you using quick dry or slow cure patches?

    1. Hi Elmo,

      I was numbering the layers as they were cut to make sure they were applied in the correct order. The first couple layers were the smallest and as the additional layers were applied they were progressively getting larger and larger in size 🙂

    1. Hi Tony,

      The use of CSM with epoxy varies depending on the type of CSM being used.

      Regular CSM sold here in the US is held together using a styrene based binder which dissolves when it comes in contact with PE or VE (which are styrene based resins). This type of CSM does not work well with epoxy for that reason. There are some manufacturers that make CSM using a powder binder that does work perfectly fine with epoxy. This material will be labeled as Epoxy Compatible. As for the CSM that is used on the backside of 1708, that is all held together by stitching. There is no binder used (styrene or powder based) to inhibit the use of epoxy.

      Thank you

        1. You’re saying an awful lot of “Bad” and “Wrong” without giving any explanation why. Please enlighten us 🙂

          1. “Amateur” Andy, please refer to the first and seventh post. It is explained there. It causes no harm, but serves no purpose and waste resources. I’ve done it before, when I was learning.

  7. it appears you’ve changed the format from real time to speeded up time with a voiceover which I think is a huge improvement. I learn by watching and doing and you’ve fit a lot more instructive doing in the same amount of time. The labeled layers was a nice touch and the metric association is great.

  8. Andy,
    Great job on your videos! Your gel coat and fiberglass work has given me the confidence to re-core a seat on a Nonsuch. The epoxy worked great with the balsa and 1708. I also got my wife an daughter involved in some gel coat color matching (that’s a miracle!).
    Keep up the good work and don’t be afraid to be “too repetitive” for us newbees!

  9. Totalboat,
    FYI – I had never tried your products until recently (I got the confidence to try them from Andy’s videos). I like that he tried many products (not married to Totalboat) but you can tell he is genuinely happy with the product quality. I am very pleased with the quality and I am also pleased with Jamestown as one of your retailers. Their shipments were fast and even had a couple of small “surprise and delights” in the package!

  10. I watch Boatworks Today almost religiously. Andy on Boatworks Today and Lou from Tales from a Shipwright are my go to guys for all boating repair/builds/fixes. They’re what brought me to Total Boat products and Jamestown Distributors. If those two guys use Jamestown Distributors products, so will I.

  11. This “WEZ” person is obviously a dolt, having spent far too much time huffing resins and not enough in practical real world work. And I’m sorry about your financial situation but, a little extra spent on epoxy where it’s properties help ensure a better process and result aren’t going to break the bank for most of us.
    But, if I and these seasoned/commercially successful experts are so wrong, by all means “WEZ” prove them wrong…with numbers, research, verified experience, and examples of your superior success and their abject failures.
    Until you can prove your yammering, pipe down and let the experts talk.
    Folks…..“WEZ” is what is known as a “troll” on internet comment sections and blogs and should be delt with quickly and harshly. The wonderful folks at TB are far too nice to deal with his/her likes. None of us have time for people who can’t backup their comments.

    1. It’s unfortunate the administrator and NickTD have resorted to the new low. My intentions were to warn inexperienced viewers that “amateur” andy’s advice didn’t come with years of experience. He is learning and is getting better, but shouldn’t be in a teaching position.

      Like most today it appears you like “feel good” comments, unicorns and Safe places. The troll is you, if you cannot recognize that the comments were help people….well, keep living the lie.

      I have nothing to prove to you.

  12. Ha. Nice job taking the bait. Guess your ego just couldn’t let it go.
    Again..”if these seasoned/commercially successful experts are so wrong, by all means “WEZ” prove them wrong…with numbers, research, verified experience, and examples of your superior success and their abject failures.”
    Come on, your statements are so absolute. Provide some absolute evidence. Or find someplace else to pontificate and condescend.
    Bye now

  13. Pingback: Making a Fiberglass Panel with Boatworks Today Andy Miller

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