HUGE PROJECT!! 30' Scarab Sport overhual

[erikgreen]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

Looks good so far. Take your time, and make sure you grind the surfaces down to good, clean glass, with no paint, loose fibers, or wood still attached before re-glassing.

Twin 1708 tabs on the stringers is probably the minimum. If it were me I'd do three layers, or maybe even four. A boat with that amount of power is going to get beat on a lot. The 8 oz cloth adds some strength, but not a ton.

Make sure also you orient the fibers on the two layers differently if you can.. IE if one layer matches the orientation of the stringers horizontally with fibers crossing vertically, try to turn the other layer 45 degrees for more strength. If you're using pre-cut biaxial "tape" this won't be possible.

If you have the hull supported on bunks or five points on jacks, then you shouldn't get warp.

Erik

 

[ondarvr]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

I think earlier you said you're going to use polyester resin, and it will work fine, but I think the laminate you're going to use on the stringers is not sufficient. 1708 is a great product and if possible use more of it, the part that concerns me is three layers of 8 oz cloth, that's not much glass for hull of that size, plus it's not good practice to use knitted and/or woven products back to back with no mat between them. I think that layup should be stronger (thicker) over the stringers.

 

[jserb]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

So what am I doing wrong? Is this ok??? Their are air bubbles all over these! I am replacing all of my stringers EXCEPT for 6 little 1ft long stringers that join the bottom of the hull to the sides of the hull. The wood in these has ZERO rott and they are in VERY STRONG condition. But i wanted to reinforce them so i took out the grinder and roughed and scuffed the area applied acetone, applied a layer of resin, wetted out the cloth then put the cloth on. however then i noticed since i didnt GRIND the surface down 100 percent flat that the roller i used to smooth out the glass was not working. so i used my paintbrush and dabbed the glass into the crevasses that the existing fiberglass had made. Now I have this! Please help!!! I dont wanna have to redo everything i do! also, a few have voice opinions on my procedure, please give me a break down of exactly how i should be laying this out. Do I have to grind in between my next layer for 1708 biax? Im using no wax laminating resin. I plan on reinforcing (tabbing in) the stringers with 2 layers if 1708 biax and then encasing the stringer with 8oz. cloth, this is more of a water sealer since the stringer will have all its support from the BIAX attaching it to the hull. The 8oz. will be used to go from where the tabbing ended on the stringer to the opposite side where the stringer was tabbed in. PLease help folkS!

 

[zach103]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

john i know your waitin on the compass.. i havn't been home due to the fact that i just moved up to school.. next time im home i will certainly try my hardest to get it to you.

 

[jserb]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

it looks like i lost my help....

 

[fire7882]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

I'm no expert, but it looks like you need more resin to me. Maybe try a few trial runs on some scrap pieces of wood.

 

[erikgreen]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

Okay, this isn't going to be easy to read.

But, first, slow down

The pics you posted of the glass on your stringers aren't good... the glass needs to lay very flat with no bubbles, so you are going to need to strip off that old glass and grind the surface flat. If it's not flat now it's not prepped properly for the resin anyway.

Once the surface is flat, you may need to add fillets.. specifically these are bits of material placed at the hull/stringer joint to make the 90 degree angle easier for the glass to make. You can use a variety of things to do this, but most people make a putty of resin and cabosil or resin and wood flour. Put that in place like grout and smooth it to a nice concave shape with a piece of plastic. If possible, lay your next layer of glass over it while it's still wet, that way you get a better bond and you don't need to smooth it completely.

Remember, 90 percent of any task in boat rebuilding is prep work.. whether it's cutting boards to size, cutting glass to size, grinding old glass and paint, or sanding surfaces. You can't skimp on prep work and expect to end up with the boat you want.

Take the time and grind the old surfaces in the boat flat, including the stringer sides (you're not replacing all of 'em?) the hull bottom where the stringers meet and a space to either side of them, and the transom edges.

Once that's done and you have a smooth or at least non-bumpy surface, you're ready to fillet and glass. If you do the prep work, the glass is very very easy and smooths out with little effort.

If you get bubbles, you have to get them out before the glass hardens. The glass has to harden against the stringers or it has little strength, and subsequent layers have no strength. So get out your grinder and remove that stuff, and start over.

Keep at it, no one learns this stuff overnight.

Erik

 

[Mark42]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

What Eric said is right on the money.


Let me add:

The air bubles in your 1708 is because it is so thick its hard to work the resin all the way through. Once it starts setting, you will not get any more saturation. So as soon as you feel the resin warming up and thickening, STOP brushing it on the 1708. 1708 takes a lot of working with a brush and roller to get the air bubles out. Thinning the resin helps.

The main function of encasing stringers in glass is to make them water proof, not stronger. Plywood stringers are plenty strong. A layer of 8oz well applied should provide plenty of water protection. Epoxying them to the hull with an epoxy putty would be more than sufficient to hold them in place.

Just my personal opinion, but I would only use 1708 on stringers if the stringer was a foam core. Then the strength of 1708 will be needed.

That is a lot of stringer to cover with glass. Pre-cut as much as you can do in one day, and use slow hardner so you have more time to work, and can mix larger batches.

I found a Sharpie marker worked well to mark the dry glass when pre-fitting pieces that need trimming or cuts for inside corners, etc. Applying pieces that are too big is a waste of material and YOUR TIME TO PROPERLY LAY THE PIECE. While you waste time gitting a good fit on a too big piece, the resin is also setting up....

After applying about 8 yards of 1708 to my Capri Hard Top, I do not envy the amount of work you have ahead. Take breaks! And be careful.

 

[ondarvr]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

If the area you just glassed wasn't in bad shape and the glass was intack, then there is no need for more glass in those spots, just leave as is.

If you didn't grind the surface 100%, which would leave it smooth, then it's not ground enough for a good bond, every square inch needs to be thoroughly sanded.

If the stringers were originally layed up with a single 8oz cloth then that's all you need, but I doubt that's what was on there and you need to use mat as the first layer or the cloth won't bond well.

On that boat I would say it was at least two mat and two roving on the stringers when built new, rebuilding it with less can and will create problems. check what you ripped out and replace it with at least an equal laminate. A single layer of 1708 would be the minimum.

1708 will at times not hold resin all that well and may drain out some, frequently it's from not applying enough resin to begin with. Wet out the surface, lay the glass in place, fold back 1/2 of the glass and wet it out with a fuzzy roller, lay it back in place and fold back the other 1/2 and wet it out. With the glass in place and wet on the under side, now you can wet it out from the top side. Make sure you have enough resin on it and don't over roll it with the fuzzy roller, it will tend to pick up the resin and can leave the glass a little dry with air bubbles.

For larger areas after you wet out the under side, pour the resin on the glass and move it around with the fuzzy roller or a squeegee. Dipping the roller in a tray is slow and eats up time that can be used to get air out of the glass.

 

[ondarvr]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

You only need to sand between layups if you let it sit for more than a couple of days between layups, or if the surface is too rough for the next layer to lay flat.

 

[Tail_Gunner]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

Odarvar can you explain why 4 layer's of biaxle glass would not be enough...once again i am questioning my methods for stringer's.. I mean if they fail it would take one big rock...


Matt seems like so much of a waste of time .

 

[ondarvr]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

TG

I may have missed something along the way, but he first mentioned 3 layers of 8oz cloth and then later reduced it to only 1 layer of 8oz cloth over the stringers.

The 1708 was only to tab the stringers in place. One layer of cloth will keep the water out, but will add little strength to the plywood, plus it won't bond all that well without mat.

I can't say what the laminate should be for a 30' Scarab Sport because I've never seen one being built in the plant, but I do know that one cloth is not a laminate I've seen being used on a small boat, let alone a 30' high performance hull.

 

[Tail_Gunner]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

TG

I may have missed something along the way, but he first mentioned 3 layers of 8oz cloth and then later reduced it to only 1 layer of 8oz cloth over the stringers.

The 1708 was only to tab the stringers in place. One layer of cloth will keep the water out, but will add little strength to the plywood, plus it won't bond all that well without mat.

I can't say what the laminate should be for a 30' Scarab Sport because I've never seen one being built in the plant, but I do know that one cloth is not a laminate I've seen being used on a small boat, let alone a 30' high performance hull.

Hmm i dont like trampling on a good thread......but i bedded in the stinger's with a 3m product 8609... its a urethane used to bed in winsheilds in all the cars we drive...strong enough to become part of the frame stronger that 4800 and 1/4 the price...followed with 4 layers of biax tape... .In other word's biaxle tape 4 layers should be by far stronger than any mat...short cuts yes...but far less resign and by far cheaper and a greater strength yeild....going on the cheap here too... yes it is getting late..:redface:

 

[ondarvr]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

TG

You used epoxy so there's no need for mat, knitted and woven products can be used back to back and as a first layer with less (little) chance of them delaminating. With ployester, mat is needed or the bond will be poor between layers and to the substrate. 1708 does have a layer of mat stitched to it so it works well by itself, the problem you can run into is that it will not conform easily to small irregularities in the surface of the substrate and leave air in the laminate. The layer of mat does help fill the uneven surface, but the small amount on 1708 won't fill every low spot. When using epoxy with biax or woven fabrics the surface needs to be prepared well (smooth), or the irregularities in the surface can be very difficult for the glass to follow without mat, so you end up with air trapped in the laminate. With polyester and at least one layer of 1.5oz mat, the surface should still be prepared well, but the laminate will be more forgiving and follow an uneven surface much easier, the more mat used the easier it will be for it to follow the surface leaving less air.

 

[Tail_Gunner]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

Thanks again Ondarvr, you articulate very well and the subject matter is by far better understood by me, sorry for the thread interuption..back on topic..

 

[oops!]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

sorry......i been away from the puter for a bit.....but john.....read these posts 3 or 4 times......SUPER info here.....

Okay, this isn't going to be easy to read.

But, first, slow down

The pics you posted of the glass on your stringers aren't good... the glass needs to lay very flat with no bubbles, so you are going to need to strip off that old glass and grind the surface flat. If it's not flat now it's not prepped properly for the resin anyway.

Once the surface is flat, you may need to add fillets.. specifically these are bits of material placed at the hull/stringer joint to make the 90 degree angle easier for the glass to make. You can use a variety of things to do this, but most people make a putty of resin and cabosil or resin and wood flour. Put that in place like grout and smooth it to a nice concave shape with a piece of plastic. If possible, lay your next layer of glass over it while it's still wet, that way you get a better bond and you don't need to smooth it completely.

Remember, 90 percent of any task in boat rebuilding is prep work.. whether it's cutting boards to size, cutting glass to size, grinding old glass and paint, or sanding surfaces. You can't skimp on prep work and expect to end up with the boat you want.

Take the time and grind the old surfaces in the boat flat, including the stringer sides (you're not replacing all of 'em?) the hull bottom where the stringers meet and a space to either side of them, and the transom edges.

Once that's done and you have a smooth or at least non-bumpy surface, you're ready to fillet and glass. If you do the prep work, the glass is very very easy and smooths out with little effort.

If you get bubbles, you have to get them out before the glass hardens. The glass has to harden against the stringers or it has little strength, and subsequent layers have no strength. So get out your grinder and remove that stuff, and start over.

Keep at it, no one learns this stuff overnight.

Erik

the wet out process is also CRITICAL for a good layup.

If the area you just glassed wasn't in bad shape and the glass was intack, then there is no need for more glass in those spots, just leave as is.

If you didn't grind the surface 100%, which would leave it smooth, then it's not ground enough for a good bond, every square inch needs to be thoroughly sanded.

If the stringers were originally layed up with a single 8oz cloth then that's all you need, but I doubt that's what was on there and you need to use mat as the first layer or the cloth won't bond well.

On that boat I would say it was at least two mat and two roving on the stringers when built new, rebuilding it with less can and will create problems. check what you ripped out and replace it with at least an equal laminate. A single layer of 1708 would be the minimum.

1708 will at times not hold resin all that well and may drain out some, frequently it's from not applying enough resin to begin with. Wet out the surface, lay the glass in place, fold back 1/2 of the glass and wet it out with a fuzzy roller, lay it back in place and fold back the other 1/2 and wet it out. With the glass in place and wet on the under side, now you can wet it out from the top side. Make sure you have enough resin on it and don't over roll it with the fuzzy roller, it will tend to pick up the resin and can leave the glass a little dry with air bubbles.

For larger areas after you wet out the under side, pour the resin on the glass and move it around with the fuzzy roller or a squeegee. Dipping the roller in a tray is slow and eats up time that can be used to get air out of the glass.

after one or two days .....the resin is still tacky to the touch.....thats good....thats why the non waxed is laminating resin....it allows you time.....especially for the larger layups.

You only need to sand between layups if you let it sit for more than a couple of days between layups, or if the surface is too rough for the next layer to lay flat.

one other thing.......ALLWAYS.....clean with aceitone before you glass....(unless you are doing a "wet on wet" layup)

cheers
oops

 

[maxum247]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

While at the outdoor market near where I live there was a guy next door who had two boats simuliar to yours. One was a Scorpion with twin 225 Evinrude's and the other one may have been a Sport, couldn't tell riding by as the paint was badly faded, but it had twin XP300 Evinrudes on it. Both appear to be in the 30 foot range, the Scorpion appeared to be somewhat newer, the other one appears to have sit in the weather for a number of years, the paint on the 300's was pretty faded.

 

[SnappingTurtle]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

it looks like i lost my help....

it looks like we lost jserb ...

 

[WizeOne]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

If you are willing to have engines shipped then it makes sense to search the whole craigslist, then hook up with a local surveyor to have them tested.

this link searches nationwide in one shot.

http://www.searchtheentirecraigslist.com/

What gives with the nationwide craigslist search. I typed in a Honda model and it said; "Your search - honda - did not match any documents."

So I just typed honda and got the same response; "Your search - honda - did not match any documents."

Am I missing something?

 

[triumphrick]

Re: HUGE PROJECT!! 30' Scarab Sport overhual

I also tried that craigs website and it also drew a blank when i entered "honda" "yamaha" or "boats"??????