Waketower install and spray foam ??

[soonerdeer123]

First of all, I'd like to say this is my first post on this forum, I've been googling boat things and I always get directed to iboats for my answers so I figured it's time to join !!!

I just ordered a Big Air Vapor wake tower for my 04 Glastron GX205 and I have a question about the install, mainly about the backing plates.. I know after reading for hours on the internet that I need to make wood backing plates for the inside of the hull to strengthen the mounts.. So yesterday I looked up in the hull where I will be mounting the tower and I see a bunch of spray in foam near the area I would be putting the wood plates, I know most folks say I need to use an epoxy between the wood and the hull to fill any voids or gaps, but can I use this spray foam as my filler ??? I would have to use a paddle bit on a drill to make it flat for the wood to butt up to but is this a strong enough material ? Or should I use the paddle bit and get all that spray foam out of there and get down to the fiberglass and use the epoxy as others have mentioned ??? I was thinking this foam would be a better option but not real sure what I'd use to bond the wood to this foam.... Any advice is appreciated !!!

 

[metriccrescentwrench]

Re: Waketower install and spray foam ??

Get down to bare glass for your backing plate, that foam compresses way too easily to be of much use.

 

[skydiveD30571]

Re: Waketower install and spray foam ??

Yep, cut that foam out of there where your backing plates will go. With the loads that you will place on your tower, you'll want solid backing (fiberglass and your wood backing plate and whatever you choose to use as a filler). Foam will compress under high loads. I used liquid nails as my filler and have had great results.

 

[soonerdeer123]

Re: Waketower install and spray foam ??

Ok, i bought Loctite PL premium construction adhesive and a 2'x4' sheet of treated 1/2" plywood... After getting all the foam out of the hull where I'm mounting the tower, I will wire brush the hull a bit to "rough" it up, butter up the back of my 5"x8" plywood plate with the adhesive, snug it up, let it sit overnight, then torque it down the next day and I should be fine ???

I know to drill the holes in reverse and feather the edges of the holes with a tapered "sanding" bit and I should be good to go ??????

 

[metriccrescentwrench]

Re: Waketower install and spray foam ??

Sounds like you've got it covered. I assume you're using large fender washers or similar on the bolts to spread the load over a large area of the plywood?

 

[soonerdeer123]

Re: Waketower install and spray foam ??

Update on this topic.... I finally got the tower installed, directions were pretty straight forward and it looks good and seems really sturdy but, I still have a question about my backing plates... I originally tried 1/2" plywood for them but the screws were not long enough to go through my hull, plywood, metal plates so I had to get 1/4" plywood.. Others have said 1/4" is sufficient but after I buttered them up with adhesive and stuck them to the boat and started to "snug" them up I could hear the plywood cracking a little as it took form of the curvature of my hull.... I let them setup for 24 hours then came back and tightened them the rest of the way.. I'm just concerned about how durable this 1/4" plywood is for use as my backing material to thicken and sturdy my mounting points ??