Any tricks to 2 part expandable foam?

[CCrew]

Before I blow all my work apart I thought I should ask <br /><br />-Roger

 

[JasonB]

Re: Any tricks to 2 part expandable foam?

If you don't pour enough the first time, you can always add more...Made the mistake of trying one big pour once....

 

[johnnybigrigger]

Re: Any tricks to 2 part expandable foam?

Mix it thoroughly in a bucket, in the boat !! If you mix it on the bench...by the time you figure out it is expanding you may leave a trail to the boat, over the side (still expanding), then into the cavity, where you find yourself short, and the trail on the floor was what you needed to top off the area in the boat Plus, it is a mess to clean off the floor, and side of the boat!<br /><br />A little something I do, pour it in the cavity without the floor, you can trim off the excess with a hand saw for a nice fit.

 

[snapperbait]

Re: Any tricks to 2 part expandable foam?

ditto on whats already said... Just want to add, wear rubber gloves of some sort! <br /><br /> The stuff sticks to skin like crazy.... Very nasty... Wears off in about a week...

 

[JasonJ]

Re: Any tricks to 2 part expandable foam?

Yeah, don't do one big pour, you will blow things apart. Is the floor already installed? If it is, run a hole every two feet from rear to front between all stringers. Elevate the bow as high as you can. Make small batches and pour. Once the foam gets to the first hole starting at the rear (lowest point), close it off with something heavy. This forces the foam into all the nooks without blowing anything out. Go to next hole and pour small batches, repeating process of first hole. Make sure the batch you pour is fully expanded before pouring the next batch. As you are working your way to the front, you are ensuring the void is completely full without causing bulging or blowouts. This worked very well on my rig. The foam adds structure and noticibly stiffens the hull when it is applied in the way I have described. And yes, I got in on my skin and had to chew the stuff off, don't make that mistake.

 

[CCrew]

Re: Any tricks to 2 part expandable foam?

Thanks guys, I escaped unscathed! That's some neat stuff though <br /><br />Jason, better than 1/2 the floor is down, my idea was that with the section that was still not in, I could take a flashlight and see whether it was filling the void. Not like I could have done much about it though.. <br /><br />I had already found one of your earlier posts, and had pre-drilled holes every 16" to use as pour points. Worked out well, could have probably gone 24" with no problems, and just adjusted the amount of the pour. I found on mine, about 20oz (10+10) was about perfect for each of the 16" sections. I'm using 4lb foam, and boy that stuff is solid! Biggest fear I had was two gunwale sections in the back that were totally closed, and had the potential to bow the exterior. Made out OK though, came out well. I'll be glassing in the rear half this weekend, I'll try to get some pics so you see the progress. I'm pretty happy with the way it's coming out. <br /><br />Thanks again, everyone!<br /><br />-Roger

 

[JasonJ]

Re: Any tricks to 2 part expandable foam?

Cool, glad its workin' for you. That stuff puts out some heat, doesn't it...

 

[Craig W]

Re: Any tricks to 2 part expandable foam?

Since this topic is still fairly fresh, I'm wondering if a few of you out there might be able to help me out as well.<br /><br />I went to start foaming project #1 today and I get the feeling that the results are going to be less than desirable. I started with a small 3' section up in the bow, and due to not feeling that the stuff wasn't working right, I've finished working on the boat for the day, not wanting to waste time or materials until I get this straightned out.<br /><br />from what I've read here and on the product's instructions, I was expecting that I'd have about just over 30 seconds to combine, mix and pour as the mixture would start expanding as mixing commenced. I'm also concerned about the effects of ambient temperature and the reaction. I've kept the A & B components inside the house meaning they should be around 75*F. I am working in the garage, I've been able to keep the garage around 50-60* and I also have the boat covered with a baseboard heater inside, I'm guessing the temp gets in the neighbourhood of high 60's.<br /><br />my results:<br />combinding equal parts of A & B about 16oz -from just inside the house, and mixing vigerously it didn't react as I had expected. Expansion seemed minimal thru the mixing stage, and at the "30 seconds" that the instructions mentioned I had to work with it, it poured out like thin honey. Even at about 4 minutes it didn't appear that the foam was expanding as it should (no where near what the canned stuff from Home Depot does.) Is it liklier that my problems are from the less than ideal temperature (is it *that* sensitive?) or is it possible that I may have picked up an older batch of foam components? (they could be 1/2 to a season old.. I'm not sure right yet) I've not gone back to check to see how it has expanded in the last couple hours, but I figure it hasn't done too much (judging by the way things have gone initially) I'm not going to continue till I have this figured out. I think my next step may be a sample pour inside my workshop in the house.<br /><br />Any help or comments would be greatly appreciated.<br />thanks

 

[CCrew]

Re: Any tricks to 2 part expandable foam?

Craig..<br /><br />If you're using the US Composites foam, they consider absolute minimum temp to be 70 degrees, with 80 preferable. Can says 65 tho. It will not expand properly below that according to them. With my garage at 75, it did start to kick at 30 seconds, about full expansion at 5 minutes, done (although still WARM!) at 15 minutes. I was pouring in 20 oz total batchs. <br /><br />Hope that helps!<br />Roger

 

[G DANE]

Re: Any tricks to 2 part expandable foam?

Craig W, CCrew and Jason.<br /><br />What about using the canned stuff from home depot ?. I did a test, leaving a small hardened portion outside for 2 months ( at the garbage )<br /><br />Is aparently didnt absorb any water at all. Can says "non absorbing, water resistant foam". Comes pretty cheap now. 10 cans, which would be 50$ should expand to 200 Gallons.

 

[JasonJ]

Re: Any tricks to 2 part expandable foam?

G-dane, was your outside sample in a container that would hold water and not allow airflow or evaporation? If not, then the experiment will be flawed. This is a common thing that occurs. Someone will see a glob of this stuff outside in the weather and assume because it isn't saturated that it would do good in a boat. Under a floor, the water stays, and after considerable time, with nowhere else to go, it starts to saturate into the foam. You could use the home product if you always trailer the boat to the water, and it is always stored under good overhead cover, but as always, I will recommend against the home product. It was designed for interior use, around windows and such, not marine environment. I don't see any problem with using it in other parts of the boat that won't hold water and is not exposed to sunlight. In the end its your boat, good luck with it.<br /><br />Craig W, that stuff is pretty sensative to tempurature. Ultimately, the warmer the environment, the closer you will get to its fully expanded volume potential. It would seem like the 60s should be okay, but you can lose up to a 3rd of the volume at that temp. If you could get the temp in the mid to high 70s, or even the 80s, then you will get your total volume. Good luck...

 

[G DANE]

Re: Any tricks to 2 part expandable foam?

Good point JasonJ !!!<br /><br />Now - for the next 2 months it will be too cold to do any poly or foam work for me here, as my boat is only covered. I will weigh the piece and try to submerge it in a plastic bag with water for a couple of months. By then we will know !!<br />The foam is actually marked outdoor as well as indoor use. I´l let you all know the results.

 

[Craig W]

Re: Any tricks to 2 part expandable foam?

thanks CCrew & JasonJ<br /><br />I guess in the back of my mind I was hoping that in some isolated detail there would be a way I could get around the temperature issue.. doesn't look like it I'll have to see if a couple more heaters in the boat will be capable of raising the temp into an optimum range.<br /><br />Luckily, I don't have to foam project number 2. I was able to remove all the foam "blocks" intact, so I can just dry them out and put them back in after new stringers and bulkheads.

 

[JasonJ]

Re: Any tricks to 2 part expandable foam?

Yeah, the temp thing is a PITA (Pain In The Arse). Last January when I started mine I was all happy, tore everything apart, and was dead in the water until late March/early April. The temps were finally in the high 60s, warm enough to start the glassing. Now I have a garage, but with no way to heat it good, it is only good for protection. Thankfully I have nothing to do on the boat right now. It will get painted in late Spring.

 

[CCrew]

Re: Any tricks to 2 part expandable foam?

"Thankfully I have nothing to do on the boat right now."<br /><br />Yeah? Must be nice!! <br /><br />-Roger

 

[JasonJ]

Re: Any tricks to 2 part expandable foam?

Actually it kinda sucks. I mounted my new bow mount Minn-Kota a few weeks ago, that was fun. I took the bow rail I had to remove for the trolling motor and made a grab handle so the person sitting/standing next to me had something to hold onto while under way. I sometimes just go out and sit and stare at the thing, trying to decide if there is something else I can do. I do have more small stuff to do, like painting it, but thats a warm-weather event. There are little piddly things I could do, but the garage is cold and I would spend more time warming it up than I would doing the piddly things. Spring isn't commin' soon enough....