Engine room soundproofing

[RobBrown]

Old Bukh 20 is out @ the moment being refurbed so I thought I'd take the opportunity of replacing the old oil & diesel soaked eggbox foam stuff currently in the engine bay. I have bought a pack of 28mm lead Quietlife panels, some dedicated adhesive and plastic fixing washers from ASAP, but before I start on the work, thought I'd ask for any tips on removing the old and cutting/shaping and fixing the new before I start. Fair amount of fittings on the engine bay walls which I don't really want to take off & re-affix. Always willing to learn from other people's experiences!

 

[Paragon]

Whilst it may be a pain, I'd take the fittings off and possibly make up blocks to mount them on and cut the sound proofing around the blocks. You wont get better access than you have now and given the cost of the new stuff it will produce the best result both aesthetically as well as functionally!

It would be worth getting some foil tape (assuming panels are foil faced) and use this for the gaps between the panels, makes for a nice finish and a "sound tight" fit! If doing overhead panels, apart from the glu, I would also use the big plastic penny washers (or similar) as well as adhesive.

Fitting is otherwise similar to tiling the bathroom but try and get the whole area covered as much as possible as any gap is a leak!

Hope this helps

John

 

[ghostlymoron]

While you're at it, i would have a good look at the layout of your engine compartment to make sure all equipment (fuel filters etc) are in the best position for maintenance as many, including mine, aren't. With the engine out, it's a golden opportunity.

 

[Babylon]

Whilst it may be a pain, I'd take the fittings off and possibly make up blocks to mount them on and cut the sound proofing around the blocks. You wont get better access than you have now and given the cost of the new stuff it will produce the best result both aesthetically as well as functionally!

Rob

I agree. You might recall that when I re-engined (Bukh out Beta in) last winter, I completely stripped the engine bay, cleaned down all surfaces and repainted them (thus getting rid of any remaining smells), finally mounting the insulation. When it came to re-mounting all the other gubbins, I made up mounting blocks to suit each component out of 19mm ply, ie the same thickness as the insulation.

With the insulation mounted in place (I used screws with penny-washers instead of the self-adhesive backing so I could always remove panels for future access), all I had to do was offer up each mounting block into position, score around it, finally remove the areas to be cut out with a stanley-knife. With the block loosely held in its place, I then covered the whole area with silver insulation tape, before drilling screws through both block and bulkhead to take the component in question.

The only exception to this method was for items (ie Henderson bilge-pumps, heater control thermostat, etc) which for reasons of clearance, etc had to be re-mounted directly to the bulkhead in their original place. In these cases, I drilled through the virgin insulation from behind the bulkhead using the existing holes as a guide, then lightly bolted the pump's feet in place to score the cutouts. It was quite tricky marking around the feet of the pump (I used a cheap thin craft knife to bend into place), then removed the unit to reveal exactly where to cut out of the waste.

As regards sizing your panels, there are two methods I used:

1 (the easy method): Where the area to be insulated was square or nearly square, I used one corner with its adjacent sides as a reference and cut the insulation to match this. I then cut the insulation panel marginally oversize and offered the whole thing up in place, squishing the piece in and guestimating exactly where to knife the other two edges.

2 (the other method): Where the area to be insulated was a completely irregular shape, I made up cardboard templates first, trimming them to fit as well as I could.

Finally, although its best to use as few panels as possible, in practice a surface might have recessed areas or be so complex (eg with fixed fuel spigots or copper return pipes poking out of them) that you might need to use different pieces of insulation. Just make sure you cover these cracks with at least two layers (the first might split) of silver joining tape.

Also, treat each remaining uninsulated area as a serious leak point for noise (it works that way) and make your best effort to insulate it.

All the best,

Jon

 

[RobBrown]

Thanks for the tips and partic. Jon for the detailed advice. I guess I already knew the answer to removal of items before fitting, since I asked the question! If it has to be , it has to be.

Yes foil sheets, so I will get some foil tape. Didn't get it from ASAP as they only had v large rolls, but I assume available from usual DIY outlets.

Any solvents or other agents to use for the old foam/adhesive or just mechanical removal?

 

[Deleted member 36384]

Glue Removal and Scribing Tips Fir New Panels

The link below has a list of adhesive removers which may be useful: -

http://www.google.com/search?client=safari&rls=en&q=adhesive+remover,+uk&ie=UTF-8&oe=UTF-8

This stuff is deigned for fabric contact adhesive removal: http://www.hawkehouse.co.uk/default.asp (Under Glue Remover In Menu)

Face Off Discs which rub away glue: http://www.hawkehouse.co.uk/default.asp (Under Glue Remover In Menu) I have used these on large panels in my aft cabin to remove old glue. Worked well, don't apply too much pressure, just enough to whip of the old glue.

With regards to fitting panels into irregular shapes, scribing is quite easy to do and very accurate. The procedure is as follows: -

1. Obtain a a compass with the clamp for a pencil, preferably with a locking bar to set the compass opening.
2. Offer your cardboard template up to the irregular edge.
3. Inspect the template and find the largest gap between it and the edge.
4. Set the compass to this widest gap and lock.
5. Place the point of the compass the top of the irregular edge.
6. Draw the compass point down the edge allowing the pencil to scribe the irregular edge on the template.
7. Cut out the irregular edge and transfer the template to your panel, mark off and cut to suit.

Tips
1. A felt tip pen can be better than a pencil.
2. Establish a datum for the area that the panel will be fitted to and use this to establish the position of the template. It makes cutting out the other regular sides easy.
3. The template does not have to be the size of the panel, just large enough to mark off the irregular edge e.g the curve of a hull.

 

[RobBrown]

Excellent tip re scribing and thanks for the links. I now know what I'm doing these coming January weekends!