Remove or Leave this Foam?

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Shoedawg

Well-known member
Joined
Feb 14, 2014
Messages
294
Reaction score
3
Location
Mountain Home, Idaho
I have a 17' Dominator (Tracker) and in the process of cleaning out the stern end. The original foam is still there and is that spray closed-cell foam that was put in by the manufacture. The cut out square holes in the front are what two plastic storage bins sit in.

The foam is in decent shape, and I am thinking it could be used to help me support some of the rear decking I plan on attaching.
IMG_0016.JPG
IMG_0039.JPG

Also what about the front side? Should it go as well? It's not in the way and is going to be under the floor.
IMG_0034.JPG
 

Attachments

  • IMG_0039.JPG
    IMG_0039.JPG
    29.6 KB · Views: 1,244
+1 on replacing it only if it's water logged.

I used very thin fiberglass sheet material that by itself would not support itself as a decking material, but with the foam behind it it's as hard as a rock. I used the same 2part expanding urethane that you've got in your boat from the mfg - polystyrene dissolves if you accidentally spill gasoline on it, and not that I fill gas in the boat or anything, but you never know when something is going to go wrong and I'd rather not have the foam supporting my floor dissolve away.

Bottom line you should be fine supporting your rear deck with that foam material.
 
I have decided to keep it. It's not waterlogged, isn't in the way, and helps me save money on buying foam for the back. Thanks for the feedback.
 
If you haven't done so already, you might want to "dig down" to the lower portions of the foam and see if it's waterlogged. Some of the thicker foam in my boat was waterlogged on the bottom and dry on the top.
 
JMichael said:
If you haven't done so already, you might want to "dig down" to the lower portions of the foam and see if it's waterlogged. Some of the thicker foam in my boat was waterlogged on the bottom and dry on the top.


I'll take a look at it Mike. I plan on making some draining holes to check it out.
 
If it's like the foam in my boat was, you can let it sit there for a year and the water will not "drain" from the foam. It's trapped in the cell structure of the foam.

BTW when I removed the foam from my boat, I weighed one section of it and then did the math to estimate total weight. It was equal to having another passenger in the boat at all time as it weighed in at 180lbs. I didn't actually weight it but I'm estimating that the total weight of the new replacement foam was less than 10 lbs.
 
Hmm interesting.....What I am thinking I need to do is drill a hole with a make shift PVC type jerry-rigged hand drill bit. Does that make any sense!!! LOL. Anyways, I need to figure out a way to get underneath it. I just stripped paint off my boat today, and did not even look into the foam issue yet. I plan on tackling it on Sunday.
 
a regular drill bit will work, just stop when you feel any resistance (IE the boat hull)

you don't need to go boring all over the place, you'll know if there's water in the foam just by the shavings your bit kicks up - there will be very obvious amounts of water mixed into the cut-up foam.
 
Cut a piece of pvc pipe at a 45* angle and tap it down with a hammer, then twist and remove and you'll have a core sample and a drain hole.
 
Capt1972 said:
Cut a piece of pvc pipe at a 45* angle and tap it down with a hammer, then twist and remove and you'll have a core sample and a drain hole.
Great Idea!! +1 Didn't think about using the PVC pipe for taking a core sample. And cutting it at 45* angle is simpler than making teeth marks.

onthewater102 said:
a regular drill bit will work, just stop when you feel any resistance (IE the boat hull)

you don't need to go boring all over the place, you'll know if there's water in the foam just by the shavings your bit kicks up - there will be very obvious amounts of water mixed into the cut-up foam.

Good to know about the shavings containing water. I was wondering how I was going to determine if the foam was water logged or not. With Capt's PVC core sample idea, I'll have a picture of what is really going on. The problem I am having with this foam is its placement. The bottom of the foam is not accessible, due to the layout. I'll know more tomorrow and keep you guys updated. Thanks.
 
I was debating the same thing, my foam looked fine at face value. I decided to pull it out and I'm sure glad I did. I didn't see water in most areas but there were pockets of trapped water at the bottom of several areas. I had sections that were completely waterlogged but only the bottom inch of the foam was affected. I don't think a core sample would have been enough for me to have known the extent of the damage. I'm no expert, this is my first project so take it for what it's worth.
 
The foam should not be water logged at all. if there is water in the foam in the core sample you'll want to replace it. The volume you have there can be done with a 1 gallon sized 2part kit (really 2x 1 gallon containers that you mix 1:1 for each pour) which will cost ~ $60 if i remember correctly. I bought mine from US Composites. Shipping was expensive, $25 if I remember correctly.
 
onthewater102 said:
The foam should not be water logged at all. if there is water in the foam in the core sample you'll want to replace it. The volume you have there can be done with a 1 gallon sized 2part kit (really 2x 1 gallon containers that you mix 1:1 for each pour) which will cost ~ $60 if i remember correctly. I bought mine from US Composites. Shipping was expensive, $25 if I remember correctly.


Is that easy to do? I'll have to do some research on it. I still didnt get to the bottom of the foam yet. To do so, I needed to remove the motor, and before I could do that I needed to build a OB stand which I did yesterday. Here is the stand I built:

IMG_0001 (2).JPG

Didn't cost very much to build, but now my motor is off the boat. Did that today. Now that its off I can tackle the foam issue, but NOW I am leaning towards stripping the whole hull of the boat since its off, and repainting. :-k
 
Depends on what you want to replace it with. if you want to use the polystyrene stuff it's as easy as cutting boards and stacking them in the cavities. BUT the manufacturer didn't use that because if you spill gasoline on it it will dissolve. Pouring urethane isn't too bad. It's a 1:1 mix, so you take two Solo cups, fill them to the same line, then pour one into the other and stir...then dump the mix in the boat once it's uniformly mixed. The trick is knowing how much it will expand, but if you're doing it one cup at a time you'll be fine. Takes about 20 minutes before you can pour over anything you've done already, so if you start with one cavity, then pour the other two you should be just about ready to pour a second batch in the 1st by the time you've done the other two. Trick is to keep the foam from seeping out when it's in it's liquid form and to build-in some design to allow the boat to shed water back to the transom drain (probably how the boat originally became water logged.

I had mostly positive results using duct tape to seal off cavities so the foam couldn't run out. It's fairly tacky, so it isn't like you're trying to contain water. Once you got toward the top of the compartments you'd want to take a piece of plywood that will cover the cavity section you're pouring, cover it in plastic (garbage bag works nicely) and after pouring the last of the foam place the board over the top of the cavity and weigh it down with cinder blocks along all the edges. Some foam will blow through, but once it hardens you can break it off. If you're using a thinner decking material the important thing is to have the foam flush to the underside of what will be your deck so it can bear the load. The foam is 2lbs per cubic foot, so it doesn't add much weight and it allows you to use thinner decking materials and save on weight/cost. I think there are progress pics on my build thread.
 
Screw it! You have me convinced. I am going to pour new foam in it. After reading your post and looking at your boat thread, as well as looking a US composites site and reading about the closed cell expanding urethane foam and its application, this seem like the right road.

If you look at page one of my boat thread, you will see some really warped and rotted wood. This just leads me to suspect that the foam is water logged. I'll post my findings later today. I am going to tear that foam out of there!
 
Wow you got a steal on that boat!!!!

Just go slow with the foam, make a practice pour into a cardboard box or something to get a sense for how it behaves, from there it's pretty straight forward.

Don't forget to plan some way of allowing water from the front of the boat to drain backwards. Bass boats seem to have piping under the foam with flush drains in the floor, I went a more simplistic route and ran vinyl tubing under the floor to each cavity so if water got in there it could drain backwards, including a line all the way up to the bow to the storage compartment.
 
onthewater102 said:
Don't forget to plan some way of allowing water from the front of the boat to drain backwards. Bass boats seem to have piping under the foam with flush drains in the floor, I went a more simplistic route and ran vinyl tubing under the floor to each cavity so if water got in there it could drain backwards, including a line all the way up to the bow to the storage compartment.

Ok, so I got ALL that foam out of the back today. It wasn't to hard to do. I used a body saw and some pry bars to remove it all.
IMG_0008.JPG

Here's what I found at the bottom of the foam. A bunch of wet dirt, sticks, just crap. I probably had about 10lbs of crap, total, from both sides. The foam itself was seated to the very bottom, preventing drainage.
IMG_0009.JPG

Here's what the bottom looked like of the foam I pulled. Was a little wet, but I don't think it was waterlogged. Anyways, I think I made the right decision to remove it, and replace it.
IMG_0018.JPG

This is the cavity where the foam went. See the wall on the upper side of the pic and that little drain channel? Well that channel was blocked up with all that foam. There was no drain tubes in the foam as I was tearing it apart.
IMG_0020.JPG

This is the whole cavity. There is drain channels in the back of this cavity. I am thinking either to pipe some PVC or flex tubing to help facilitate drainage. Another idea is to just create a elevated floor, just above the drain channel in the cavity, then fill in the foam on top of that. Got any ideas??
IMG_0021.JPG
 
yup - buy a 50' roll of aluminum chimney flashing - very inexpensive, it's very thin, easy to work with, and you can partition those sections off. If you need to rivet two pieces together to make it wider no biggie, just cover the joint well with duct-tape so the foam doesn't get through it.
 

Latest posts

Top