Surftech Repair, Need Help Installing Divinycell

General Discussion
1

Two surftech boards need repair. One is a 6’10" Rusty Piranah Quad, the other is a McTavish 9’0" Original.

The Rusty had rail damage which I ground down into fresh Divinycell, Ditto for the McTavish which suffered a parking lot accident on the nose.

Now I need to put some fresh divinycell into the repair, but I’m not sure what is the best way to do it. I’ve got all the repair sites beveled out into the surrounding glass. The damages in both locations did not descend down beyond the Divinycell. So I have only ground down into it.

I saw one board repair site in which the beveled repair site was covered with a layer of cloth and painted with epoxy, on top of this was placed some Divinycell, and these were vacuum bagged on. After the expoxy set up, the Divinycell was ground to the proper height and then the surface fiberglass and resin were applied.

This technique seems to result in fiberglass being inside the board where it normally would not be. It would seem better to bond the Divinycell plug to the existing Divinycell with some type of adhesive that has similar mechanical properties, and then to overlay with the outer glass and resin.

Can someone point me in the right direction here?

Thanks

Anthropisces

2

Post a photo of the damage. Depending on the size, D-cell may not be needed. In any case, you must vac-bag it on.

3

The (McTavish) Blue Board had a couple of cracks in the nose due to buckling (run over by an SUV). Just the corner of the nose was run over. It produced a split on the top of the board dead center on the nose and also as a crack on the bottom which had a bit of a “wave” in the material an inch away from it. I was concerned that the damage might be much worse than it was, so I ground away the material as shown in the photos to be sure. The bottom area which was ground away is now probably 9 inches (23cm) in diameter the top is about 5 inches in diameter. Maybe I went a little overboard, but it is what it is at this point.

On the bottom, at the deepest point I probably ground down about an eigth of an inch (3-4mm) into the divinycell. I think it might be tough to get a piece of divinycell in there because of the shallowness of the repair area. The same goes for the top. If the divinycell should be put back on, should it be done through the method I describe in my first post? I got the info about the repair strategy from the “boardlady” site I think I am interpreting her advice correctly but I’m also looking for more input.

On the Rusty (green paint), the damage was on the rail. In that area I went a little deeper but still not down below the divinycell. That area is also smaller (about 4 inches (10cm) long and 2.5 inches (6.3cm) wide) . For both boards I kept sanding until there was no more evidence of damaged foam.

I’m procuring all the materials and equipment for board repair, and want to learn as much as I can. I have a pretty good working knowledge of materials and have done lots and lots of hand layups on boats and surfboards mostly with epoxy, but never vacuum bagged before.

Any advice about any aspect of these repairs would be greatly appreciated. Although I first want to learn what basic repair strategy I should adopt, I also want to learn other things about the repair.

For instance I’m not sure what the weight of the fiberglass cloth is on the McTavish or the Rusty. I’ve looked at it magnified though and can probably match it pretty closely.

I’m not sure what grade of Divinycell is used on the boards. I ordered some 5lb H-80 scraps for pretty cheap from fiberglasssupply.com since they were the only source I could find for small quantities.

I am jumping in with both feet, which will include airbrush painting (my dad is pretty good at it and will help). But I would like to know a good brand of paint and primer to use. I have read that linear polyurethane is a good choice. I’d prefer to mix the colors myself and want to learn more about that too.

If you would be so good as to comment I would appreciate it, especially on the basics of how to proceed with the repair.

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4

Any specifics in terms of any materials for the job and suppliers and equipment recommendations are also appreciated.

I am pretty inexperienced, but I do work a lot with advanced materials in my job including rohacell, lastafoam, and a whole bunch of other polymers, metals and non-metals, solvents, coatings, and all sorts of processes and testing. If you can lead me in the right direction, I won’t disappoint you! :slight_smile:

Thanks

Anthropisces

5

According to Surftech’s ads, there’s at least one layer of fiberglass under the divinycell. See scans, below.


6

I can already see one area where I strayed from what the board lady does. I have feathered out into the adjacent areas before vacuum bagging the divinycell onto the gouge. It seems that she removes the material in a pretty localized way, then bags on the divinycell, then feathers the whole thing out, then puts the final glass on. So now I’m already feathered out and have not yet put in any divinycell. On the Rusty, the grinding is still pretty localized with a distinct oval of foam forming a depression.

I did not go into the bottom layer of fiberglass (opposite side of divinycell).

7

The best advice I could give you would be to check the boardladys site thoroughly. I think she mentioned that you can buy the paint for Surftechs from Surftech but it’s crap? You may also want to try taking the board to your local panel beating supply shop and ask them to colour match a paint for you. Santa Cruz uses acrylic lacquer for painting their boards but urethane paints chemically bond to epoxy so urethane will bond better. Hope that helps.

8

If the damaged area has already been filled flush with the surrounding surface, forget the D-cell. Laminate a couple of layers of 6oz cloth over it, hotcoat, fair it in. To finish, mask the area thoroughly or you’ll be cleaning off overspray later. Sand the area to be painted 220 to 320. Hit it with a light coat of rattle can primer. All the defects, holes etc will show up. Sand the high stuff off with 220, blow it off, and prime again. Fill the pin holes with spot putty (Bondo, 3m, etc) and let dry about 4-6 hrs. Sand with 220-320, prime, repeat again if needed. Depending on where you are, find a paint/finishing supplier for auto body shops. If you bring in the board, some of these places can match and mix the LP paint right there. Matching paint colors by eye is difficult, but you can get very close. Keep in mind that the original color has changed because of UV. To match, get yourself a color mixing wheel from an art supply store, and buy the primary colors needed according the wheel. Test mix the colors on a scrap of cardboard using an artist brush, and test them for match on the board. Do this is sunlight, never under artificial lights. Mix up a larger batch in an airbrush bottle, using LP reducer to thin it. Keep in mind that light colors will sometimes darken under the clearcoat, so test using a clear rattle can acrylic over your potentially matching color on a test scrap. Spray the color on in 2-3 light coats and stay clear of the masking edges or you’ll have a line. After at least 8 hrs, apply the LP clear in 2 coats. After 24+ hours, use 1000 grit very lightly and hand polish.

You sure you really want to do all of this? The paint alone will cost you more than having an experienced repair shop do it for you without the headaches that for sure you’ll encounter. Step back and look at the big picture. You’re putting time, effort, money into a production-line import. Do you know why these are painted in the first place? Sand one completely down sometime and you’ll see. Blank defects/repairs, a patchwork of D-cell and cloth scraps because nothing is wasted. If you like this kind of board, just have it professionally finished by one of the authorized surftech repair places (Eva trains them). If you have the painting skills to attempt this same thing on your new car, then by all means go for it. If not, would you really want to practice on it?

9

Thank you for such a thorough description. I will be doing the repair myself. I think that by studying the advice you give and on Eva’s site, that I can do a decent job.

I did not know that Surftech/Tuflite boards were assembled in a patchwork fashion. If they are, I’ll be interested to encounter it. I’m hoping to get hold of one that is beyond repair and do some dissection on it.

I don’t want to take the board to a repair shop for a few reasons. I don’t necessarily trust them to get the job done right, or to do it in a timely fashion. I don’t want to rely on them if I want a quick turnaround time in the future. I can also help out my buddies with their repairs.

There is a pretty decent materials, (including paint ) supplier here in West Palm Beach called “glue products plus”, I’ve spent about five thousand dollars on that place for my boat restorations in the past. They can mix up some paint in small quantities. Perhaps I’ll become interested enough to do some mixing myself.

My dad used to be a very accomplished taxidermist and is pretty handy with an airbrush. I have only painted with a brush, roller and spray can.

Of course learning anything of value is generally bloody expensive. I once painted the topside of a 25ft boat with paint that I thought was catalzyed but had only been thinned with Xylene. When I left it that evening, it was a beatiful thing, when I observed it the next day, it looked like it was coated with dried mud. Five gallons of denatured alcohol, ten pounds of rags and six hours later, it was ready for another few hundred dollars worth of paint.

I am a rank amatuer, almost guaranteed to dissapoint you as I attempt to execute your advice, but I hope you will keep providing it anyway.

Thanks

Anthropisces

10

Although the photos look like the material has already been faired flush with the surroundings, that isn’t the case. All of the repair sites require filling, which I intend (until advised otherwise) to fill by vacuuming on Divinycell. The size and depth of the patchesrequired are mentioned in a previous post.

Anthropisces

11

if it were me, I’d forget about the dcell altogether, patch in layers of cloth and just lam over the thing.

paint or resin color match as necessary.

KISS.

12

Just for the sake of argument, let’s say I do need to add Divinycell foam. The Board Lady’s site shows one repair in which fiberglass cloth was layed between the existing Divinycell and the new peice being installed. Couldn’t one simply bond the new Divinycell to the old with epoxy or an adhesive designed to work with the Divinycell. I haven’t penetrated through the Divinycell, just into it.

I respect the comments that I shouldn’t replace the foam, and perhaps that’s the route I’ll take (although not for the rail on the Rusty Piranah). But when one does need to insert foam what is the best procedure in a case like mine?

13

Contrary to what it may have looked like in the first photos, I had not filled the damaged areas. Here are some photos of the McTavish getting some Divinycell vacuum bagged onto the repair site. The technique I used is an imitation of the advice given on the site of Eva-M. Holman.

I bagged 1/8" Divinycell onto the nose and 1/4" Divinycell onto the bottom. I’ll provide some photos of the grinding, laminating, fairing and finishing processes in another post.

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14

Here are some photos of the Surftech Rusty Piranah repair so far. Repars have been done according to info on the “Board Lady” site.

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