misc. reinforcing questions

[Ericfox]

A couple things...

Do you guys reinforce the nose? I figured it is good for subs if you hit the bottom, but not sure what else it would do? I don't want to put a hole in my ceiling to hang my ski for no reason.... I am thinking it might be better just to make sure I sub in waters where I know the depth?

If you do reinforce the nose, do you use a little filler w/ epoxy down there like the bond line, or do you use foam? or does it matter...

I am laying 1708 biaxial. It is a little tough to get the very edges to lay down when the edge of the glass is over a curve... would you just let it hang out over the edge a little and sand it down when it drys, or do you really try to get it to press down onto the surface?

It seems to be a little hard on all the edges to get the glass to stay together as I squeegie it out.... do you not worry much about edges? just sand down when it dries? the edges just seem to pull apart as I run over them with the squeegie...

Who did Paul Lehr's method of rolling some carbon tape up like a fishing pole and putting it in the hood lip for reinforcement.... still cant figure how I was doing this wrong, but after I wetted the 2" carbon fiber tape I bought, it just would not roll up... kept on unraveling... maybe I have to twist it up? I dont know...

Thanks.

 

[Frosty]

I did the nose of my RN - after I smashed it into the sandbard and busted a part of it off. after that I had to rebuild it a little.

i used 2 layers of 6.5 oz biax on the outside to hold it together. Then two layers of 8.5 on the inside - one layer enough to cover the damage, the second slightly larger.

Then I covered that with a layer of 17oz biax even bigger than the other layers. then I did the entire nose, from under the pole bracket all the way to the waterbox area, from one side to the other, in a layer of 17oz.

it's cracked a few more times hitting bottom since i did this two years ago, so this past fall i installed a Taylor Curtis made Carbon kevlar nose reinforcement piece.

and yes, on some of the areas if you have some ends that don't lay perfect - after it dries I'd just go back and grind those pieces off.

 

[Ericfox]

cool. Think you would have reinforced it before smashing if you had to do it over? think its better just to watch how deep the water is, and fix if you happen to bite the bottom?

anyone know anything about the hoodlip question from above?

 

[Frosty]

cool. Think you would have reinforced it before smashing if you had to do it over? think its better just to watch how deep the water is, and fix if you happen to bite the bottom?

anyone know anything about the hoodlip question from above?

I already reinforced the nose of the new project RN i am working on... I have a problem with watching my water depth... as in I just don't seem to care about it... LOL I hit bottom to some degree every time i ride.

I would say that if you are doing the sides, and already have the motor etc out, then just do the nose too.

 

[Ericfox]

Frosty- Did you use foam in the nose to even it out? then glass? Did you hang your ski from the ceiling? I am going to get an eye bolt and screw it into the truss over my garage I guess... hope that works... I may get two to split the load between two bolts/trusses...

Someone fill me in on what I'm doing wrong about the hoodlip CF rolling from above....

 

[Frosty]

Nope.... just took my time fitting my 6.5 then 8.5 and finally 17oz. The 6.5/8.5 works well for bending and following the recesses in the hull. The 17 oz was a little more tricky. I did it all while the ski sat on the shop stand.

I did use foam however, around the pole bracket mounting area to fill the deeper recess on each side. for that I had to flip the ski upside down, sand well... pour in the foam, let it rise like a loaf of breat, then just took a sharp knife and cut it flat. then used a dremmel to sand an parts smooth with the hull. then glassed over that area down into the sides.

I never used the "roll up" method you are referring to. you might be able to fill the hood lip area with epoxy/hardener/filler to get rid of the deep recess around the lip.... just a thought.

 

[Ericfox]

Could you describe the shape that you cut the glass for the nose? Did you use little strips? or did you try to do it in one piece? how did you do the top of the nose when it was on the stand... wouldnt that be hard as hell?

Someone must have done the "roll up" hoodlip method.... help?

 

[E rok Wilbs]

I don't know exactly how you're getting the shape but if you wrap it around something to get the shape from then you can't get it to maintain that shape you could try using some wax paper. It releases pretty well from the resin and you have to sand it anyways if you're going to lay more glass to it. What are you trying to reinforce? The inside hood lip? Have you thought about just using a high density two part foam and then sanding it?

 

[Ericfox]

I don't know exactly how you're getting the shape but if you wrap it around something to get the shape from then you can't get it to maintain that shape you could try using some wax paper. It releases pretty well from the resin and you have to sand it anyways if you're going to lay more glass to it. What are you trying to reinforce? The inside hood lip? Have you thought about just using a high density two part foam and then sanding it?

Paul at LPW has a method of rolling the cf tape and then putting it in the hood lip and then putting another layer of tape over that to kind of smooth it out to make the trasition... It seemed bullet proof... just cant figure it out... I'll just call him if nobody knows... seems like this is not a popular way to reinforce the hood lip area.... maybe I should do something else? Other suggestions???

 

[crammit442]

Paul at LPW has a method of rolling the cf tape and then putting it in the hood lip and then putting another layer of tape over that to kind of smooth it out to make the trasition... It seemed bullet proof... just cant figure it out... I'll just call him if nobody knows... seems like this is not a popular way to reinforce the hood lip area.... maybe I should do something else? Other suggestions???

I'd pass on that idea. The rolled up piece will be full of voids.

 

[Frosty]

if you didn't already do the sides, i would do everything together, to give a good structure.

fill the bond line - i think this was covered in a previous thread you had.

I precut all my glass first and do a dry fit for good placement and trim.

Lay the ski on it's side as to do one side at a time. Cut some 6.5 oz in about a 3" strip (2 strips - one per side). Lay them the entire length of the hull... from bulkhead to the nose. Then do the same thing with a 6" wide strip (2 strips - one per side). Then cut a strip that is the entire length that goes from hood seal lip to the bottom. as you lay this piece in it will, because of the shape of the nose, it will naturally extend down on to the bottom of the hull, so when you dry fit your pieces in you can cut this piece to follow the contour of the side where it meets the bottom.

doing this will actually reinforce the nose quite a bit and keep it tied to the side reinforcement.

Now, to do the top of the nose/pole bracket area...

flip upside down fill in the recesss on each side of the bracket area. precut your biax so that is shaped like the nose and extends down the side a bit to over lap the side reinforcement you layed. working with the ski upside down will help get a good flat lay, but you will still need to squeegie it good.

hope that helps...

 

[Ericfox]

I should have elaborated... I already did the bracket area with 2 strips about 3"x15" traveling from the hood lip towards the nose spaced about 2" apart on the bracket area. Then one piece over the whole bracket area extending onto the hoodlip area and up a little short of the gas hole but not onto the sides. Then a large piece covering the whole area of the last piece and extending well onto the sides. This is all 1708 biaxial.... probably overkill... but I'm a nube at glass....

Next I would do the nose, then the firewall about down to the intermediate shaft. Then the sides... doing all the layers on the sides at one time... of couse sanding any areas already glassed before overlapping...

The only other place I would do so many layers may be the nose. Everywhere else I just planned on filling the bondline with some filler, then one full layer 1708 and then one layer 5.7 oz carbon fiber over that.

I might reconsider the hoodlip reinforcement due to the air voids as previosly mentioned.... maybe just some filler and cover...

 

[E rok Wilbs]

I'd pass on that idea. The rolled up piece will be full of voids.

Ya it seems like it would not be adding much strength because it would only be contacting the lip in two spots unless the contours match up perfect.

Honestly I would you epoxy with a filler or just two part foam if you want to save some weight then just sand it to the desired contour. From there all you need to do is lay up the glass/carbon/kevlar. Like Frosty said, definitely cut your pieces of cloth before you put any resin down.

 

[Frosty]

I

I might reconsider the hoodlip reinforcement due to the air voids as previosly mentioned.... maybe just some filler and cover...

there ya go.


it also sounds like you might be going on reinforcement overload.

I've never done the firewall, and my sides and nose are as I described - increasing size strips (3", 6" and full side) with the first two strip at like 6.5 oz, the final full side using the 17oz.

don't go too nuts with the stuff. I think most people go overboard.

 

[E rok Wilbs]

don't go too nuts with the stuff. I think most people go overboard.

I know I did on the past few skis I've done. Honestly I think one layer of a 17-19 cloth is plenty.

 

[Ericfox]

I know I did on the past few skis I've done. Honestly I think one layer of a 17-19 cloth is plenty.

I will only do one layer of 17oz biaxial on the firewall/sides and then a 5.7 oz cf over that... the cf shouldnt add too much extra weight... I just wanted to try the experience of laying the cf and maybe add a little coolness...

 

[Ericfox]

is there ANY advantage of laying glass over the firewall? Maybe sealing it? Maybe ties the two sides together a little bit?

 

[Ericfox]

if you didn't already do the sides, i would do everything together, to give a good structure.

fill the bond line - i think this was covered in a previous thread you had.

I precut all my glass first and do a dry fit for good placement and trim.

Lay the ski on it's side as to do one side at a time. Cut some 6.5 oz in about a 3" strip (2 strips - one per side). Lay them the entire length of the hull... from bulkhead to the nose. Then do the same thing with a 6" wide strip (2 strips - one per side). Then cut a strip that is the entire length that goes from hood seal lip to the bottom. as you lay this piece in it will, because of the shape of the nose, it will naturally extend down on to the bottom of the hull, so when you dry fit your pieces in you can cut this piece to follow the contour of the side where it meets the bottom.

doing this will actually reinforce the nose quite a bit and keep it tied to the side reinforcement.

Now, to do the top of the nose/pole bracket area...

flip upside down fill in the recesss on each side of the bracket area. precut your biax so that is shaped like the nose and extends down the side a bit to over lap the side reinforcement you layed. working with the ski upside down will help get a good flat lay, but you will still need to squeegie it good.

hope that helps...

I was told that the increasing size stip along the sides is something that the surf guys should do, but not the flat water guys... dont know why... maybe just because surf guys need extra reinforcing.

 

[E rok Wilbs]

is there ANY advantage of laying glass over the firewall? Maybe sealing it? Maybe ties the two sides together a little bit?

Honestly I wouldn't worry about the firewall,mine is only two layers thick and I'm not even going to reinforce it. Trust me all that weight adds up. Good luck though, sounds like you already have a tons of info.

 

[Ericfox]

Honestly I wouldn't worry about the firewall,mine is only two layers thick and I'm not even going to reinforce it. Trust me all that weight adds up. Good luck though, sounds like you already have a tons of info.

I may make up a fake sticker for a mini fire-extinguisher to make up for some weight lol... shhhh don't tell. I think it's bull that I even have to carry one. This is after getting mini battery and xmetal waterbox of course... If I do the firewall at all then maybe I will just do it with the CF only...