Engine foam replacement?

marietta_ken · **Joined:** Fri Nov 11, 2011 10:16 am **Posts:** 38

Mine is a crumbly mess. Have seen a variety of options around, including a steep quote from the local dealer. Anybody replace their's yet?

Obie · **Posted:** Sun Nov 13, 2011 8:15 pm

There are kits you can buy that has the metal-faced foam, spray glue, and metallic seam tape. Overtons use to carry these. Try Goggling marine sound insulation.

marietta_ken · **Joined:** Fri Nov 11, 2011 10:16 am **Posts:** 38

Obie wrote:

There are kits you can buy that has the metal-faced foam, spray glue, and metallic seam tape. Overtons use to carry these. Try Goggling marine sound insulation.

I've seen those, but not sure if that's the route I want to go. The 2.5" egg crate stuff has better sound absorption, and is needed on the hatch cover side walls to fill the space there. I'm looking hard at some egg crate (fire rated UL94) from McMaster Carr. Am also contacting some other marine foam mfr's to see if they'll sell directly to me. One site has a fair price on 1" egg crate/convoluted foam, but I want 2.5".

As an aside -- I contacted FW about this as well. They first said they were looking for a new supplier. Later they called and said they could get me the ONE big piece for underside of the hatch for $145. Each of the two side pieces was like $35. Hoping to find a lesser expensive solution bc the front wall of the engine compartment will also need replacing at some point.

marietta_ken · **Joined:** Fri Nov 11, 2011 10:16 am **Posts:** 38

Update: Went with the 3" fire-rated 94HF1 egg crate foam from McMaster Carr. http://www.mcmaster.com/#sound-absorbing-foam/=gnbcp4 Item number is 9710T66. Note that is the 54" x 54" sheet. Going to the 3" foam in the 97" length takes you to a diff fire rating (Cal 117). I tried to get a comparison as I feel good about UL 94, but ultimately couldn't find anything meaningful. End of story is I went with what I felt was the safer play.

I also wanted to try to improve upon the adhesion of the foam so that it wouldn't fall off again. Part of the falling off was likely due to the degradation of the foam, but I think the limited glue surface area was a problem as well. As you can see in this picture, the foam spanned large areas and was glued to some structural ribs:

I decided to cut my replacement foam out around those ribs to let the foam sit directly on the large flat surfaces for better adherence. This took a little extra work, but I feel better about it. Here's the finished foam, waiting to be installed:

You see I had to make the foam out of two pieces because the 54" x 54" foam sheet couldn't span the 63" width needed. Frankly it worked out better imo because it was easier to work with for cuts and such. If you orient things just right, one 54" x 54" sheet will give you the underside and two ends of the decklid for about $100. The quote I got from Four Winns for who-knows-what replacement was closer to $215 for the same coverage.

Here are the end pieces:

In case you are wondering how I determined the shape to cut...I taped a piece of heavy (kraft) paper to one half of the engine OPENING so that it basically formed a cover over that half. I then took a razor and, using the inside edge fiberglass as a guide, I cut out the paper to the exact shape of the opening. Here's the template:

The last part of this equation is adhesion. I already have some 3M Super 77 and the 3M 74 Foamfast spray adhesives on hand. However, I wasn't quite sure about the flammability ratiing of those -- even after reading the 3M data sheets. Called 3M today and it seems I'll be OK with either the 74 or the 80, which has an even higher temp rating. Since the 74 can handle max 180 deg F, I think I'm OK with that. If someone wants to chime in and tell me that the engine bays get that hot, please do so. I can't see how they would...

Now that I have my adhesive answer, I'll install soon and post pics of the final result.

St. Louis Dave · **Posted:** Wed Mar 14, 2012 5:45 pm

I'm looking forward to your results and mostly the sound improvement. I'd love to add more foam to my boat to limit the amount of noise my motor makes.

ric · **Posted:** Fri Apr 06, 2012 4:43 am

Same, I already have picked out what I want. It's in line after the gauges get replaced.

http://www.dynamat.com/products_car_aud ... liner.html

SanDiegoBoater · **Joined:** Wed May 23, 2012 2:32 pm **Posts:** 1

Hi all,
New to the forums, will post pictures after this coming Memorial weekend trip to Laughlin/Havasu. I have a 1998 Horizon (purchased new Nov. 1997) and the engine compartment insulation is falling apart. I have been researching replacements and found my here! I have read the posts here and got a couple of good ideas, but wondered if anyone has used the Volvo Penta “QL Sound Absorbent” (http://www.volvopenta.com/SiteCollectio ... ent%20(Eng).pdf) or the Johns Manville “Incombustible Hullboard” (http://www.jm-oem.com/files/pdf/CI-85.pdf). Both products seem very good and affordable…I can get 2X3 sheets of the Johns Manville product here in San Diego for $12.00 a sheet. I figure with the needed attaching devices I can do my project with either product for about $60.00. Both are marine products and have good fire protection and sound reducing properties.

I know there’s a lot of knowledge on this forum and would appreciate any thoughts anyone has on the topic.

Thanks

rapa123 · **Joined:** Tue Jun 06, 2006 8:32 am **Posts:** 69

Hi Ken,
I realize this post is over 10 years old but, I'm curious. I have a FW 2006 244 Funship 5.7GXI VP DP. I'm currently going through the exact thing as you did. Although my FW is a deckboat, your hatch looks identical to mine on the underside including the wood bracing. I'm surprised mine stayed in place all this time. My dealer checked with FW in which they stated that they're still using the same eggcrate foam but, in black at $8.50 sq. ft.
That was a great idea of using the kraft paper for a template. I'm not comfortable having someone else replacing the foam. I'm a builder therefore, I'm comfortable with doing the job myself. There's too many variables of someone not doing it right. This way I can blame myself....LOL. I also want to stick with the eggcrate due to its great sound absorption. I've been conversing with 3M by email in which they have recommended the following adhesives; 74, Super Trim 08090, Hi-Strength 90. Since this hatch is so big/heavy, I'll be working on it in place w/o removing it as well. I also same type side pieces as well. I'm thinking of installing insulation hangers as well for better support, especially if I don't cut out for the wood bracing. As for cutting/shaping the foam, I'm going to try to use an electric kitchen knife. After some searching, many people stated that it works great on foam. With that being said, I haven't found anyone yet that used one for eggcrate foam. If you don't mind, would you please elaborate on how well yours has been holding up along with what you ended up using for adhesive and cutting? I would sincerely appreciate it. Thanks.
I placed a post on mine back on October 6, 2022 here on the forum;
https://www.smwebhead.com/phpBB3/viewtopic.php?f=4&t=23807

rapa123 · **Joined:** Tue Jun 06, 2006 8:32 am **Posts:** 69

Wish I could have seen this installed....... :roll:

www.iFourWinns.com

Engine foam replacement?

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