Insulating engine compartment

[Simon J]

Winter project: Insulating the engine compartment of my 1978 Morton & Hersloff 36

While insulating I came across old insulation- Lead backing with either fiberglass, or asbestos . Does anyone know if this could be asbestos? I am replacing all area easily within reach, but will go further if it is asbestos and should be removed. Also, I've heard that I can just remove Fiberglass?asbestos exterior and press my new insulation/heat shield /noise reduction diectly onto the lead backing.
Comments anyone??
Simon J

 

[C lectric]

I can't help you with the fiberglass/asbestos. To determine which it is I suggest to clip a small sample and send it to a remediation company or lab for identification. One you know which it is then you can decide how to proceed. Even if fiberglass wear a good respirator and eye protection. Fiberglass can throw small fibres which can irritate your eyes and , although not as bad as asbestos to my knowledge, can be a lung irritant also.

As far as just pressing your new stuff onto the asbestos I question that. Maybe so but be carefull. I too have lead sheet and don't secure anything to it. Unless the lead is absolutely clean the adhesive may fail to bond properly. Further, what I have seen over the years is the lead develops splits. THe foam will help support it if you do not use the lead as part of the securement.

Do not depend upon any glues/adhesives for portions over top of the engine, mechanical securing only, or the new insulation may fall on the engine.

I have insulated my compartment for noise using the Soundown but secured it with screws and LARGE washers. The pins I found were very expensive and if you needed to adjust something they were a throw away. They sure looked nice though, the little domes.

Since then I've used SS LARGE FENDER washers but have also made my own of 1/8 Lexan with a hole saw. Just wire wheel brush the Lexan edge after cutting to smooth the edge. THey work well.

I used screws on about an 8" square pattern. Screws were #6 pan head and just long enough to securely fasten to the overhead right through my lead sheet while lightly compressing the washer into the foam just a bit without going all the way through the cabin sole.

Fender washers may require an intermediate washer size between the screw head and the hole size of the fender washer.

 

[Simon J]

Thank you for the great advice, so far I have used double masking(these days we all have plenty of those) also I have been removing the lead backing, painstakingly difficult!

 

[C lectric]

Actually lead is a good sound killer simply because of density. It does not vibrate.
However if you are already well into it then carry on but otherwise consider leaving what is still there and just cover it.
I left mine for that reason. Just protect it.

 

[Datenight]

Do not depend upon any glues/adhesives for portions over top of the engine, mechanical securing only, or the new insulation may fall on the engine.

I have insulated my compartment for noise using the Soundown but secured it with screws and LARGE washers. The pins I found were very expensive and if you needed to adjust something they were a throw away. They sure looked nice though, the little domes.

Since then I've used SS LARGE FENDER washers but have also made my own of 1/8 Lexan with a hole saw. Just wire wheel brush the Lexan edge after cutting to smooth the edge. THey work well.

I used screws on about an 8" square pattern. Screws were #6 pan head and just long enough to securely fasten to the overhead right through my lead sheet while lightly compressing the washer into the foam just a bit without going all the way through the cabin sole.

Fender washers may require an intermediate washer size between the screw head and the hole size of the fender washer.

I did the same on the green boat. Run the driver in reverse to get it through the insulation or it will wrap up and tear the foam. Have to admit I discovered this by accident.

Rob

 

[Keysdisease]

What stops noise is mass, that's why lead is such a good noise barrier. Todays lead replacement is Mass Loaded Vinyl (MLV) used in the same weights a lead was used, usually 1 or 2 lbs per sq ft. A typical insulation will include a de-coupler layer on the back which enhances the noise barrier and an absorption layer on the front to reduce reflective noise or reverberation.

If you're already taking your lead out, clean it up and put in back in, it's an excellent noise barrier. The fiberglass or asbestos on top was a "build in place" absorption layer. In 1978 it was probably not asbestos, but checking is prudent.

Go over the newly cleaned and re-installed lead with a vinyl/foam insulation (cheaper, easier) or a lead fiberglass (more expensive, difficult, incombustible) insulation. These 2 type products are same/same performance, 2" thick w 2lb vinyl will perform as well as 2" thick 2 lb lead, the differences being cost, ease of install and combustibility.

These insulation products are available in a variety os sizes. With noise, performance is simple: More is better. A 1" 1lb product will reduce high and mid range noise, 2" 2lb will reduce that as well as lower frequency noise as well.

Available space usually dictates some of these choices, there is never enough room. Also note that if your hull sides are insulated that is considered optional in todays best practice, at least with a barrier product. An absorption product is preferred on hull sides to reduce reverberation, but barriers are considered unnecessary, noise out the side is seldom a concern. Overheads, forward bulkheads, sometimes aft bulkheads, yes.

As C lectric and Datenight have mentioned, adhesive and mechanical fasteners are necessary if you want the insulation to stay installed. As well as the driver in reverse trick wrapping drills and screws with some masking tape will also reduce the "wrap and tear" effect of drilling or screwing through todays insulation.

Your typical choices, vinyl/foam or lead/fiberglass

 

[Sailor of Fortune]

I would doubt there is asbestos with the lead. I believe it was illegal in the year your boat was built and its use stopped a few years before that. Probably f/g or another material over the lead but get it tested if concerned.