Help with my restoration. Nida stringers/deck

No unremarkable cheap junk comes out of your shop, the fact you could even build it is testimony to that. Let's see in a highly stressed condition what would I prefer: a giant hard break here spot, or a material with the same exact modulus as the rest of the hull shell?? Just asking.

 

By so far our customers are fine with my products, and willing to pay twice the price than for the best selling plastic crap of similar size.

Your question is a bit off topic in regards to this repair job, right?

And to come to a end:
I do not support your mad attempt to turn this thread into another pissing contest (your specialty)............hence

over and out!

 

No it is you who comes with the mindless reply's, I can only imagine what your tooling looks like ,now go slop something together.

 

Maybe you guys can agree on these next question.

-I do not need matt (CSM) between the layers of biax +45/-45 when using epoxy....correct?

-I think I need to make a cap over the top of the stringers because the polypropylene core of the Nida-core is exposed...correct?

-What would be the best material to do this with. I can cut strips out of the 12oz 50" biax. How well will a 1-2 inch strip of cut out biax conform to a sharp 90 degree bends on the top of the stringers? should I use something else besides the biax? I have seen cloth used where they remove some strands on the edges so that it will bend easier. What do you think?

- In the belly of the boat, Regal did a good job of laying 1 or 2 layers of Roving over the stringers/bulkhead and tying it into the hull. Now that the stringers are removed, I am left with a buildup of roving material on the hull creating an uneven surface. I have sanded with a grinder, but it is thick and somewhat impervious to my grinder. Should I start out with a layer of matt to compensate for this uneveness, not worry about it, or do I need to grind all the old roving completely off the hull?

Thanks

KP

 

I have put some answers in your quote.

 

Thanks Herman.

- I had to sand the old roving to prep it for the new tabbing that will take place. In the process of grinded the old tabbing (woven roving) I ran into a lot of dry roving glass that had to be sanded out. Here are some questions I have.


SHOULD I ADD A LAYER OF GLASS TO THE HULL?

- I have some flex in the hull in the bildge area. I am 180 Lb and if i shift my weight back and forth I can feel a very slight amount of flex in the bildge area. I also saw a couple of tiny stress cracks in this area. I have run a ground a few times in this boat on shallow sand bars. I can not see any stress cracks in the out side of the hull coresponding to where the stress cracks are. I can also see a very faint shadow in other areas inside the hull when I pass my hand on the outside of the hull obstructing the light.
Is this normal or is the glass a little thin? I thought about adding a layer or two of biax 12 oz to the inside of the hull. The entire hull now is nicely abraded from the 36 grit grinding disk. It is uneven however due to indentations or tracks where the old plywood stringers were. My question now is should I fill the tracks with a fairing compound first so that the glass will have a nice flat surface to adhere to?

- When I lay in new glass, should I go with a 50 " width and try to cover the entire bottom of the hull?. Should I worry about running glass up the sides of the hull, or is that not necessary.

-How much time do I have between laminations before I am required to sand? I am using a medium thickness slow set epoxy.

Ty

 

Don't bother. Some flex is quite normal. Also don't grind off what you don't need to, the bulk will add to the "heft" of the laminate.

Grand these out so they're wider and fill them with thickened epoxy, a 50/50 silica/milled fibers mix will do fine.

Perfectly normal, just don't walk towards the light unless "it's your time".

The 'glass doesn't really care honestly. In fact the more irregular the surface , the better the bond so just go for it, you'll have plenty of other "smoothing" work to do. Fairing compound has no business being anywhere near a structural element, unless it's on top to finish things off.

I'm not completely sure what you're talking about here, but running up the sides of the hull will strengthen things a good bit and is a mandatory thing when your sole goes back down. If you're thinking you'll make it stronger with some full length/width layers of fabric, then save yourself the time and money. Structure is the easiest way to make it stronger, not laminate thickness. Besides there is such a thing as too stiff, when things just break, instead of giving a little under load. Don't over think this puppy, it's just a boat repair thingie.

Pot life and working times are dependent on many variables. Ambient temperature, the size of the epoxy mass, the amount and type of filler used, humidity, your mother's maiden name, how many children you have, etc., only you will be able to judge this and of course this comes with experience with the particular brand you're using. Spread out your epoxy mixture into a thin sheet and avoid using glass or metal containers as the will accelerate the heat build up, which kicks off the epoxy cure process.

 

The trick of the alu tube is excellent...

Thanks Richard and Herman for the help with your answers. You save me a lot of typing...Thanks again.

On polyester small motor boats I use glass bubbles for the paste of the fillets, It's cheaper than phenolic microballons, it's lightly elastic so it won't break if the hull is a bit old and soft. It's also impervious to vibrations, or cyclic flexing.

For the kind of stresses that will have a small hull a good large fillet made in a low density paste plus the tapes is enough, and that helps to not create hard points on rather thin hulls, generally a bit flexy as the builder saved on the rovings...

As you are never sure that the polyester of an old hull is not "contaminated" (high content of water in the resin, old oil gone in the hull etc) I prefer also to use large surfaces of gluing.

On a new boat, or a bigger boat a different approach has to be used...

kpiazzisi, it's always better to laminate fresh on fresh. Plan your work with this goal in mind as that saves a lot of work. With the Raka resin, you can re-laminate without sanding within the 24 hours if the weather is not too humid. I've sent you a PM, but we'll continue here as we have the help of Apex and Herman...

 

A rule of thumb (literally) is when the epoxy is clean (no greasy layer, known as blush or aminecarbamate), and you are able to press your thumbnail into the epoxy, you can still laminate over it without sanding.

This rule of thumb works best. It is very hard to predict overcoat times, as there are just too many variables, including the resin, temperature, but PAR mentioned a couple of others as well. He forgot to mention the stock exchange market and the position of the moon relatively to your project, but I guess we can forgive him.

 

Nice that we brought it back here from PM!

All said above. And said by the right people!

So, go ahead and lets see the results.

Richard

 

Thanks guys. I know I ask a lot of questions, I appreciate you hanging in there for me.

So the consensus is to not use a surface veil or layer of biax over the bottom of the hull. A thin hull is to be expected in a boat this size, and stiffening the hull by way of adding extra laminate to the shell of the hull is not a good idea.....is this correct?


I was hoping to get the stringers and bulk heads set in today (Saturday). The problem is that I do not have the microsheres to make my fillet compound. I have the resin and a gallon of Cabosil. The fiberglass store is closed today. Are there any other options I can use to make the fillet compound? What If I cut up some of the biax into 1/4 inch strands and mix with the cabosil? If necessary, I will wait until next week. I don't want the structural integrity of the boat to come down to the fact that the fiberglass store was closed on the day I set the stringers into place.

TY

 

Would work, but you can do that yourself with sawdust. (fine dust, no grain)

The cabosil fibre mix, or the glass bubbles Ilan mentioned are the common mix on FRP surfaces though. (the fibre, glass or cotton, is providing some strength, the others are just fillers)

Mix yourself I would say.

 

Apex1

I think I got this straight.

-The Cabosil is used for thickening the resin to a Peanut butter consistency and the Micro spheres add strength?

-I am assuming too much Cabosil will weaken the compound?

-If I cut up small strands of glass to roughly 1/4 lengths, that would be adding strength, but make to fillet compound difficult to work with ....I am assuming?

- I have the byproduct available from sanding the old tabbing (PIC attached). Would this work? Would it be considered more of a filler or more of a strengthening material added to the resin?

- If I made saw dust, I would add that along with Cabosil...correct? The saw dust would not be considered a Mircosphere and would not add strength...correct?

 

I've decided to wait until Monday and get the Micro Bubbles as Ivan suggested. Now I have an excuse to that the kids to Bush Gardens. I got to take advantage of this Florida weather.

Take Care
KP

 

You can add milled fibers if you are worried about the shear strength.Fiberglass coatings is up there by you.