Glue?

[gizmo_21]

Hey guys

I need some help

I'm trying to glue a piece of stainless steel to fiber glass.

Reason:

I'm trying to strengthen my transome of my 17' sangster runabout. This is what i am doing:

So what do you guys recomend as a adhesive

Ry

 

[gotmudd]

Hey guys

I need some help

I'm trying to glue a piece of stainless steel to fiber glass.

Reason:

I'm trying to strengthen my transome of my 17' sangster runabout. This is what i am doing:

So what do you guys recomend as a adhesive ry

i might be wrong but i don't think you will find a good enough adhesive to bond the two together. the reason being that you are trying to join two things of dissimular nature. you might try "5200", it is a marine adhesive/sealant, by itself you would have to have a way to clamp it and let it set for 48hrs [ i think thats the cure time] but the way that stuff seals you could probably thru bolt the stainless plate to the back of your transom by using stainless bolts washers and nuts by following this proceedure, drill holes through metal and transom[4 should suffice] then remove plate and fill holes in transom with "5200" smearing some at least '1'inch around hole and also put a bead around the outside edge of the plate itself and lay some zig-zag beads through the center of the plate, then you can put two bolts through plate pick it up and slide it together, tighten you bolts down let the glue set set and you're done. i might add, don't get it on you, it don't like to come off easy

 

[metalmacguyver]

What he said.

I recommend epoxy and scuffing the surface of the stainless so it can get the best mechanical bond possible as it wont be able to get any type of chemical bond.


Use bolts as well and seal them up good with a marine type sealant.

 

[gizmo_21]

What he said.

I recommend epoxy and scuffing the surface of the stainless so it can get the best mechanical bond possible as it wont be able to get any type of chemical bond.


Use bolts as well and seal them up good with a marine type sealant.

I think i know where you guys are coming from!!!

Apply the epoxy to the back of the stainless steel after scuffing it considerably, once this is done and hardened, apply the 5200 to both the stainless and the fiberglass, use several smaller screws as well as clamps and allow to dry, Keep the several smaller screws in the transome and then attach the boat engine!!! This sounds good to me... i was thinking of a urathane of somesort and i've now read up on the 5200 seems it might work

thanks
Ry

 

[Mark_88]

I would also suggest plywood on the inside of the transom and bolt through steel/glass/wood...the fiberglass it self should be strong enough but depending on what size engine you're mounting the plywood wouldn't hurt...

but make sure you seal everything up...especially below the waterline...and by the looks of your diagram only two would actually be below the waterline...

Is the glass cracked or are you thinking of mounting a heavier motor?

 

[gizmo_21]

I would also suggest plywood on the inside of the transom and bolt through steel/glass/wood...the fiberglass it self should be strong enough but depending on what size engine you're mounting the plywood wouldn't hurt...

but make sure you seal everything up...especially below the waterline...and by the looks of your diagram only two would actually be below the waterline...

Is the glass cracked or are you thinking of mounting a heavier motor?

well, see i am mounting a heavier motor!! but i'm not sure of the wood in the transome!!! the glass isn't cracked or anything, i'm just beefing the transome up alittle just to make sure!!

 

[gotmudd]

What he said.

I recommend epoxy and scuffing the surface of the stainless so it can get the best mechanical bond possible as it wont be able to get any type of chemical bond.


Use bolts as well and seal them up good with a marine type sealant.

won't need the epoxy with '5200' but scuffing the surface of the stainless will definitely help as well as thru bolting liike i said with stainless hardware and like someone else already stated plywood on the inside will mean that you can tighten the bolts pretty darn tight without breaking through the fiberglass

 

[mkpecor]

go to home depot and ask them for this stuff called liquid nails, it comes in a tube this stuff is the strongest shit you will EVER USE. 100% stronger then apoxy dode. if you tryed to rip the alumanum peace you are putting on it would bring the fiberglass with it. if you cant find it then go with apoxy next best thing.

 

[dirtsquirt]

Hey guys

I need some help

I'm trying to glue a piece of stainless steel to fiber glass.

Reason:

I'm trying to strengthen my transome of my 17' sangster runabout. This is what i am doing:

So what do you guys recomend as a adhesive




Ry

STOP STOP STOP Bad idea with steel any steel,

If you want to beef up your transome us 5/8 marine grade plywood shape to fit from your keel to upper transome from gunnell to gunnell ! laminate to your hull using the same glass/resin as your hull is made expoxy or pollyester DO Not mix type's ( loss of bonding) use not waxed first coats only (same reason ) use a waxed (tinted) if you like Gelcoat for finish.

If your are going to go with a bigger motor u have to build strength across the whole transome. ( it will tear out from the gunnels)

Sand your boats transome (really well) to remove the gelcoat/wax very important!! when it looks good sand it some more!!!

Do not use metals in your transome Notice how all metal boats use wood mounts on the transome (vibration relief ) avoids ELECTROLICE'S Thats why wood transome mounts and ZINCS...

 

[Will]

How about some pictures of the boat. Assuming you want to stiffen it, the stainless steel is worthless in that application. Marine plywood is the right stuff. DO use epoxy--it will adhere to cured polyester resin and it will encupsulate the plywood. Polyester is not a good adhesive. Epoxy is more flexible, which is good because the plywood and fiberglass expand at different rates.

What type of power does this have? An outboard or I/O drive I would expect it to have 4 layers of 3/4" plywood laminated together like this--

If's it's in inboard then a little stiffening is all you need and even 1/4" marine would be enough. If you are trying to overpower an outdrive or outboard, you need to look at the junction between the motorbeds and the transom.

 

[gizmo_21]

Wow guys, it sounds like some of you have done this before

Stock: 1970 65 Hp Evenrude outboard

New Engine: 1996 90 Hp Johnson outboard

Weight Diff: Approx. 45 Lbs

it's a 1975 - 17 foot Sangster...
i'll grab some pictures for you guys!!! the stringers and everything were done somewhat recently...

Essentially all i'm trying to do is distribute the thrust from the enginer throughout the back of the transome, totally understand that my method is a "quick and dirty" one and by adding stainless inside as well it should (10-15%) increase the strength

O and i'm seeing most newer style boat using steel now.. like this

the Parker not the seawall
where they detach the engine from the transome.. with steel (aluminum)

 

[Will]

Without having seen the boat, I would say that's not the best method of strengthening it for more power. Steel has no strength when it's installed flat like that. A few big washers under the bolts would do as well. If you are trying to stiffen it, plywood is much stiffer.

Assuming you do have a 3" transom, I would use steel to build gussets (knees) that were bolted through the transom to the outboard bracket and crossways through the bottom stringers. That is what supports the weight and dynamic forces. Right now, assuming there are no knees, the face of the plywood is sending the forces to the sides and bottom of the hull. There's nothing you can do to strengthen it unless you bond in a few layers of fiberglass tape around the junction of the transom and sides to reinforce it.

This is a little tug I built a few years ago. The transom is only strong right in the middle. There is a plywood gusset (knee) on either side that ties the motorboard into the bulkhead on the front of the seat. Without these gussets the motors weight and force would go out to the sides which are not meant for the strain. I don't think you should overpower without reinforcing this part of the boat. Your hull to transom junctions may be strong enough for a 65, but maybe not for a 90. Especially since there is a moment-arm with that bracket hanging off back there. It may only be 45# heavier, but the additional torque it puts on the transom is 45*length.

I think a new 90 is a heck of a lot more motor than an old 65.

 

[gizmo_21]

Especially since there is a moment-arm with that bracket hanging off back there. It may only be 45# heavier, but the additional torque it puts on the transom is 45*length.

I think a new 90 is a heck of a lot more motor than an old 65.

I'll send some pics tonight for sure,

and your totally right about the additional moment caused by the extra weight as well as the extra thrust (a 90 is fairly stronger then a 65 you are right), i'm sure the transome will handle this... as we how do i explain this (i'll just get pics lol) the only thing i'm worried about is the "T force" in the diagram below, i'm trying to distribute that force throughout the trasome instead of only on the two little "feet" that bolt the engine to the transome... and since the force will take the stiffess path i'm hoping to distribute more horizontal force and have less moment.... and i'm pretty sure mine not 3" thick of plywood (i wish it was), i think mine is 2"... but i will certainly grab pics of that two...