Sealing Tray Components

[///M3]

Working inside my Superjet tray after defoam and I want to get everything before I close it. Read tons of build threads but can't find a definitive answer on these:

Sealing cooling/trim lines from inside of tray - glass or 5200?

Sealing cooling/trim lines from outside of tray (engine bay) - same question

Green stuff Yamaha uses to seal - anything needed in these areas?

Drive shaft tube (where it meets the bulkhead and the pump tunnel) - seal with glass or 5200?

Lastly, holes on top of pump tunnel - how to seal Those?

Thanks for any help.

 

[Sanoman]

I would go with 5200 for everything inside and out. Glass the holes with epoxy on the pump tunnel
And 5200 comes two ways,7 days to get hard or 24 hours.Use the 24 hour 5200 unless you have time

 

[///M3]

Thanks for the advice. I got to thinking about foaming and came up with this dilemma:

I already glassed in drains in the rear and I plan to use EPS foam to fill the bottom. I am widening my tray in this process and I am going to need to pour two part foam in the sides after I have the wide tray kit glassed in. I understand that the two part foam expands and fills all the gaps, including the gaps in the bottom of the tray. Won't that two part foam ruin my drains by filling all the gaps and closing the drains? May be a stupid question but I don't want to ruin all the work I've done thus far.

 

[Sanoman]

Lowes or Home Depot sell 1" thick sheets of foam.A lot of guys will cut to fit pieces to fill the space under the tray with this foam.Also gives a solid feel when you glass the tray back over it.

Should be a number of threads on this subject

 

[///M3]

Lowes or Home Depot sell 1" thick sheets of foam.A lot of guys will cut to fit pieces to fill the space under the tray with this foam.Also gives a solid feel when you glass the tray back over it.

Should be a number of threads on this subject

Yeah I already know about the EPS foam. I am going to use that inside the tray. My question is when I pour 2 part foam into the sides of the ski (to fill the gaps w/ wide tray kit) its going to go down into the tray as well and fill ALL the gaps thus potentially screwing up my drains.. I know others have used drains and EPS + 2 part foam but I'm wondering if it mucks with the drains.

 

[Vumad]

Yeah I already know about the EPS foam. I am going to use that inside the tray. My question is when I pour 2 part foam into the sides of the ski (to fill the gaps w/ wide tray kit) its going to go down into the tray as well and fill ALL the gaps thus potentially screwing up my drains.. I know others have used drains and EPS + 2 part foam but I'm wondering if it mucks with the drains.

You could flip the ski and fill the gunnels with 2 part foam before you close it up. If its a wide tray kit so there are no walls, you can shape the foam with drop plastic as it it expands. Wear gloves. The foam wont get throuh the plastic but it gets uncormfortsbly hot before its done expanding. Just dont pop the foam. You cant touch it or move it once it has expanded. Let it move under the plastic and you can push in some but if it doesnt move with pressure or redirect you can actusllh ,ove it. The foam pops if you poke at it before it cures. Dont worry, youlld see exactly what i mean as it expands.

Alternatively, if there are no hangups, you can wrap the kit kn plastic and pour the foam and let it push up to the kit. Obviously the shape has to be comducive to removing jt after the foam has cured so you can go back and put the eps sheets jn the bottom of the tray.

 

[///M3]

You could flip the ski and fill the gunnels with 2 part foam before you close it up. If its a wide tray kit so there are no walls, you can shape the foam with drop plastic as it it expands. Wear gloves. The foam wont get throuh the plastic but it gets uncormfortsbly hot before its done expanding. Just dont pop the foam. You cant touch it or move it once it has expanded. Let it move under the plastic and you can push in some but if it doesnt move with pressure or redirect you can actusllh ,ove it. The foam pops if you poke at it before it cures. Dont worry, youlld see exactly what i mean as it expands.

Alternatively, if there are no hangups, you can wrap the kit kn plastic and pour the foam and let it push up to the kit. Obviously the shape has to be comducive to removing jt after the foam has cured so you can go back and put the eps sheets jn the bottom of the tray.

Good ideas. What if I installed the wide tray kit (epoxied them in to the ski walls, taped the seams, etc.) then flipped the ski over and poured the two part foam in the sides? That seems like it could work.

I have not used two part foam yet so your insight is helpful. What is the two part foam like once it has cured, hard to sand, impossible to sand? Is it anything like the stock foam where you can break it out w/ a screw driver? Also, you mentioned plastic so it won't stick. What kind of plastic or materials can I use so that it won't stick to parts of the ski that I don't want it to? Thanks again.

 

[Sanoman]

Yeah I already know about the EPS foam. I am going to use that inside the tray. My question is when I pour 2 part foam into the sides of the ski (to fill the gaps w/ wide tray kit) its going to go down into the tray as well and fill ALL the gaps thus potentially screwing up my drains.. I know others have used drains and EPS + 2 part foam but I'm wondering if it mucks with the drains.

Oops! l see that you did mention the EPS foam in a post!

The 2 part foam is easy to sand

 

[///M3]

Oops! l see that you did mention the EPS foam in a post!

The 2 part foam is easy to sand

That's good news then. I was also thinking I could seal everything up, screw some really long M8 bolts (my drain size) in and the pour the two part. Then after it expands/dries I could unscrew those long bolts and there would be a path... crazy idea but I think that could possibly work. Would the two part foam be too strong that it would hold those bolts in and not let me unscrew them?

 

[Vumad]

Good ideas. What if I installed the wide tray kit (epoxied them in to the ski walls, taped the seams, etc.) then flipped the ski over and poured the two part foam in the sides? That seems like it could work.

I have not used two part foam yet so your insight is helpful. What is the two part foam like once it has cured, hard to sand, impossible to sand? Is it anything like the stock foam where you can break it out w/ a screw driver? Also, you mentioned plastic so it won't stick. What kind of plastic or materials can I use so that it won't stick to parts of the ski that I don't want it to? Thanks again.

The stock foam is 2 part. Fresh stuff is crisper. Sandability is probably affected by density. I have only used 2 lb which is good for gunnels. Sanding is easy, and even easier with a drywall rasp.

I saiddrp plastic. Its in the paintsection. Visqueen is thicker and works well. You can use a trash bag id you like. It doesnt matter if pieces of the plastic get stuck in a fold or whatever.

Youcan use the tray kit as a templet. I suggested that, just make sure there arent any angles the foam would go into that wouod prevent youfrom removing the tray kit if thats a necessary step in your process.

2 part foam is supereasy to work with since i learned i can dam it and use drop plastic to work a complicated shape. Only hard part about foam is it expands immediately. Its not resin you mix for 30-60 seconds and then have 5-20 mins to work. Foam starts expanding almost immediately and cant be stired or pokedat after it begins expanding. Make your plan because you get about 10 seconds to stir and 10 to pour. You cant make a plan on the fly. It expands like a mushrrom cloud until it hits something to changedirection.

 

[///M3]

The stock foam is 2 part. Fresh stuff is crisper. Sandability is probably affected by density. I have only used 2 lb which is good for gunnels. Sanding is easy, and even easier with a drywall rasp.

I saiddrp plastic. Its in the paintsection. Visqueen is thicker and works well. You can use a trash bag id you like. It doesnt matter if pieces of the plastic get stuck in a fold or whatever.

Youcan use the tray kit as a templet. I suggested that, just make sure there arent any angles the foam would go into that wouod prevent youfrom removing the tray kit if thats a necessary step in your process.

2 part foam is supereasy to work with since i learned i can dam it and use drop plastic to work a complicated shape. Only hard part about foam is it expands immediately. Its not resin you mix for 30-60 seconds and then have 5-20 mins to work. Foam starts expanding almost immediately and cant be stired or pokedat after it begins expanding. Make your plan because you get about 10 seconds to stir and 10 to pour. You cant make a plan on the fly. It expands like a mushrrom cloud until it hits something to changedirection.

Great info. Thanks! Two more dumb questions - when the foam hits something such as a trash bag, won't it push the bag outwards? would cardboard work better? Also, any idea how much of an area the foam covers per ounce or other measurement?

 

[Vumad]

Great info. Thanks! Two more dumb questions - when the foam hits something such as a trash bag, won't it push the bag outwards? would cardboard work better? Also, any idea how much of an area the foam covers per ounce or other measurement?

Yes. It pushes outward with substantial force. If you dont want to shape after then youd have to use wood, fiberglass or some other substantial dam. Ifyou do use cardboard, cover it in plastic.

Yes, the plastic will fill up like a baloon. Thats why i mentioned wearing gloves. Building a jigfor the foam canbe a lot of work. If insteadyou lay plastic, then use you hand and/or a piece of wood you can direct the expansion.

Imagine you have a 2ft x 4ft box 4 inches deep. This would be an easy shape to make a lid for. But image the shape is instead very irregular and not smooth on top. The foam expands up and out, but unless you waste a lot of foam, you wont be able to cover the entire bottom without waste, so the expabsion wont fill it out. If you cover it with plastic, and as it expands you keep you hand in the way, it will expand sideways instead of up. Once you get it into an area you want, you can move you hand so it continues sideways into another area instead of up and out of your project.

Use a combination of these techniques. If you need a flat surface of foam on a gunnel, use wood. If you need a sponson filled which is curved but smooth, use plastic and a piece of cardboard.

Its way simple man. Buy a baloon an have someone blow it up with you hand in the way. The plastic just keeps you hand off the chemicals.