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Installing an Illusion tower - a few questions and some pointers needed


chadwick02

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Hey everyone,

I have finally collected enough courage to install the tower on my boat. Next Tuesday is the date we set. As many of you know, I purchased an illusion tower off a fellow crew member last fall (and I am just now getting the nerve to take the plunge and do the install…).

A buddy (a fellow Bu owner) and I will be doing the install. We are both very competent mechanically and are relatively versed in fiberglass work. None of us have drilled holes this big in fiberglass before, nor have we installed a tower. We feel confident that we can do this, but I a few questions:

1) Is there a specific distance from the windshield or back of the boat that the tower legs should be mounted. Could someone with a 21LSV and an illusion tower measure the distance from the end of the windshield to the front of the tower leg?

2) With the tower I got the two base legs, and I believe either 4 or 6 good sized bolts to bolt the legs onto the gunnels (spelling??) Do I need anything else to mount these legs securely? Should I put some type of mat between the tower leg and the fiberglass, or put some silicone…etc in there? Or does the tower leg just sit right on the fiberglass and bolt through?

3) Lets talk drill bits for a sec. I am familiar with the reverse method for drilling fiberglass and rounding of the edges to prevent spidering. It has worked fine for me on small holes, but I am skeptical for these large holes. I remember reading on here something about a cone shaped progressive drill bit. I cannot find anything now when I search. Should I get one of these? Anyone know where to get one? If not one of those, then I want to get a brand new (standard) bit to use (mine are all beat up anyhow). Is there a specific type of bit or metal I should be looking for? Are the expensive supper carbide bits what I should look at, or are the cheap ones better since they are a little softer?

4) Anyone know what size holes to drill? We figure holes that are just big enough for the bolts to snugly fit in, but maybe there would be a reason for them to be slightly bigger or smaller??

5) Speaking of hole sizes – should I be drilling hole(s) to run speaker\light wires through? Anyone got any good ideas on what size to make those, or can I just ball park them to adequately fit the wires through? Is one good sized hole on the port side sufficient, or should I put a hole on each side for future use?

6) Do I need to do anything to brace or support the underside of the gunnels to support the tower? Or are they already good and strong? Should I just simply drill, bolt, be done with it, and not worry so much??

Is there anything else anyone can think of that would make this go smoother??

Sorry for all the long questions. I hope people don’t read this and think Im a wacko and not respond. I just need all the pointers and encouragement I can get before I start major surgery on my baby!!

Thanks everyone!

Chad

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I can't answer the rest because I've never had mine apart, but here's my contribution:

3) The Unibit is available at Home Depot (I bought one there a few years ago), which means that Lowes probably carries one as well. Very nice for drilling through gel coat.

6) Our Illusion does have some metal backing plates on the bottom side of each gunnel & even if you didn't get any with the tower, I would highly recommend using something to reinforce each side. That's just too much weight & leverage to not use something to reinforce that area & spread the load a bit.

Good luck & let us know how it goes.

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6) Our Illusion does have some metal backing plates on the bottom side of each gunnel & even if you didn't get any with the tower, I would highly recommend using something to reinforce each side. That's just too much weight & leverage to not use something to reinforce that area & spread the load a bit.

Plus1.gif I agree 100%.. You will have to put a plate on the underside of your gunnel or it just won't be safe.

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I agree with the metal plate comments. Our tower has 3 bolts per side. The metal plate is one piece (approx 2 inches wide X 10 inches long X 1/8 inch thick. Don't have my boat close by so I can't measure. suffice it to say though that the length should be long enough to encompass all 3 bolts, plus an extra inch or two on each side.

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Thanks guys.

Ive got a chunk of plate alumnum kicking around. Its thick, about 3/8", but I will be able to cut a few plates out of it. Thanks for the idea and the dimensions!

Any idea what size holes to drill (and if the unibit will go large enough)?

Any idea where to place the tower on the gunnel?

Edited by chadwick02
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We installed our own illusion tower, there is almost no wiggle room - less than a quarter inch. It's not like installing any other tower because it doesn't flex. Put the tower on the bases and measure between them, then go to your boat and see where that measurement puts you. On our boat the tower bases are right near the edge of the gunnel and they angle in just a little so take measurements at the front and back of the base. Our boat is an 05 so my measurements from the windshield wouldn't be the same. Ours is 10 inches back from the windshield. I think someone with an 04 would have to measure for you. It would help you alot if you could look at another boat with the illusion tower on it just to see how it angles in and where it sits on the gunnel. The best advice I can give you is measure every possbile angle. Then measure it again. I think we walked back and forth from the tower to the boat no less than 20 times before drilling. Good luck - you will love that tower.

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We installed our own illusion tower, there is almost no wiggle room - less than a quarter inch. It's not like installing any other tower because it doesn't flex. Put the tower on the bases and measure between them, then go to your boat and see where that measurement puts you. On our boat the tower bases are right near the edge of the gunnel and they angle in just a little so take measurements at the front and back of the base. Our boat is an 05 so my measurements from the windshield wouldn't be the same. Ours is 10 inches back from the windshield. I think someone with an 04 would have to measure for you. It would help you alot if you could look at another boat with the illusion tower on it just to see how it angles in and where it sits on the gunnel. The best advice I can give you is measure every possbile angle. Then measure it again. I think we walked back and forth from the tower to the boat no less than 20 times before drilling. Good luck - you will love that tower.

Thanks for that great info - im glad you mentioned the angle issue, or I would think something was wrong for sure.

Should I be putting any type of thin rubber mat between the tower and the gunnel? Should I use some silicone or epoxy? Or is there no need to do that?

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I can look when we get home, but I want to think that there is a gasket of some sort there.

Thats what I was sorta thinking, but who knows. Let me know what you find.

Chad

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1) Is there a specific distance from the windshield or back of the boat that the tower legs should be mounted. Could someone with a 21LSV and an illusion tower measure the distance from the end of the windshield to the front of the tower leg?

I don't have this boat, but I do have a suggestion. On my '06 iRide the illusion tower just clears the rear view mirror when it is tilted back and the top of the tower tilts all the way down to the dash. If you can get the tower up on the boat you may want to figure out where to mount it by measuring that it clears the windshield.

Is your illusion tower the type that is counter-balanced? I believe in '06 they added a tension spring to counter balance the weight of the tower so it was easier to lift and lower.

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I just replaced mine, so I didn't have to drill or measure anything, but I can give some insite.

Use double sided tape under the bases, thats what was there when I took the old bases off. I removed it and put on some new strips.

Below the gunnel there should be the adjuster for the cables. That is all thats needed under there, no plate. It is a thick piece metals that extends past the base on both sides. If you dont have it then I suggest a plate of some kind, or some wood covered in FG.

As for wires, drill the middle whole to pass the wires through.

I think the worst part is tightening the adjuster if you have if. There is not a lot of room to turn the botl in, and it needs to be about 3 inches in the screw.

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You guys be sure you are talking about the same thing. The early boats won't take the late tower with the counter balance unit. You can use the late tower but the side panels where counter balance goes is too close to the hull on the early boats. You can still use a late tower but you have to leave all the under gunnel stuff off. The old tower will fit the old hulls if the width is correct.

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Just to clarify – The tower I will be installing is the stock tower off a 2004 VLX. It is the old style tower with only 2 sets of pre-drilled holes for racks. It is going on my 2002 21LSV. They both sit on a SV23 hull, however my hull is a diamond, and his was a wake. Before the purchase we both measured widths and everything seemed like it would line up fine, I guess I had better check that again before we start drilling!

As for the spring assist – I do not think this tower has it. In any case, the boat spends all season in the lake tied to our dock. I would only fold the tower down for winter storage in our garage.

Calilsv – that double sided tape; was it under the entire base (minus the holes)? Or was it just in a few spots? Was it something similar to that 3M double sided foam tape that is, maybe 1/8” thick by 1” wide?

Also – when you put the bolts in the holes, was it a very tight fit? (cant imagine why it wouldn’t be?)

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1) Is there a specific distance from the windshield or back of the boat that the tower legs should be mounted. Could someone with a 21LSV and an illusion tower measure the distance from the end of the windshield to the front of the tower leg?

12-14" is a good general dimension, but feel free to match it up with one out there.

2) With the tower I got the two base legs, and I believe either 4 or 6 good sized bolts to bolt the legs onto the gunnels (spelling??) Do I need anything else to mount these legs securely? Should I put some type of mat between the tower leg and the fiberglass, or put some silicone…etc in there? Or does the tower leg just sit right on the fiberglass and bolt through?

There are 3 per side. I saw that you have some aluminum for a backing plate, you need to use this. Once you have located the bases to the gunnel and drilled the holes, fit the backing plate up there and ensure that it will sit flat against the underside of the gunnel. What you don't want is it fitting against a curve, where the plate will be stressing just the outside edges. If so, either machine the plate or fill in the glass to achieve a flat contact area.

This brings us to another point. Depending on the year of the boat you may have PVC tubes glassed to the underside of the gunnel as a wire chase. If so, you will need to cut and grind this tube out prior to drilling the holes for the bases. It's a nasty job, you'll need a small air die grinder and a few bits, some engineering to hold the wires out of harms way while you cut out the tube that is surrounding the wires, safety glasses, ear muffs, mask and a good vaccum. If you have a new enough model that you do not have the PVC wire chase, consider yourself very very lucky.

Base plates sit right on the glass. No need for rubber mats, etc.

3) Lets talk drill bits for a sec. I am familiar with the reverse method for drilling fiberglass and rounding of the edges to prevent spidering. It has worked fine for me on small holes, but I am skeptical for these large holes. I remember reading on here something about a cone shaped progressive drill bit. I cannot find anything now when I search. Should I get one of these? Anyone know where to get one? If not one of those, then I want to get a brand new (standard) bit to use (mine are all beat up anyhow). Is there a specific type of bit or metal I should be looking for? Are the expensive supper carbide bits what I should look at, or are the cheap ones better since they are a little softer?

I know everyone has an opinion, so here's mine. Use a new drill bit (newer kind with pilot tip) if you are worried. Drill the hole full size right from the start. Buy a good countersink bit. Use it on all holes to bevel the gelcoat way back so it will never touch the bolt. Consider it done.

4) Anyone know what size holes to drill? We figure holes that are just big enough for the bolts to snugly fit in, but maybe there would be a reason for them to be slightly bigger or smaller??

A snug hole will be too tight for all 3 bolts to align nicely. Drill size should have a little clearance.

5) Speaking of hole sizes – should I be drilling hole(s) to run speaker\light wires through? Anyone got any good ideas on what size to make those, or can I just ball park them to adequately fit the wires through? Is one good sized hole on the port side sufficient, or should I put a hole on each side for future use?

If you are going to use both speakers and lights, drill two holes each side just for them.

6) Do I need to do anything to brace or support the underside of the gunnels to support the tower? Or are they already good and strong? Should I just simply drill, bolt, be done with it, and not worry so much??

Drill it, bolt it, and be happy.

Is there anything else anyone can think of that would make this go smoother??

Pray for no wire chases.

Sorry for all the long questions. I hope people don’t read this and think Im a wacko and not respond. I just need all the pointers and encouragement I can get before I start major surgery on my baby!!

You're a wacko and we know, no sense hiding it.

Peter. :)

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Calilsv – that double sided tape; was it under the entire base (minus the holes)? Or was it just in a few spots? Was it something similar to that 3M double sided foam tape that is, maybe 1/8” thick by 1” wide?

Also – when you put the bolts in the holes, was it a very tight fit? (cant imagine why it wouldn’t be?)

Screws had a little wiggle room. The tape they used was one piece along the whole length. I used some 3m I had around and covered the whole thing twice.

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I looked at the metal backing plate this weekend (located on the underside of the gunwale). I think my original estimate was 10" in length. I didn't have a tape measure, but I would say it is closer to 16-18 inches. Measurements aside, it runs the length of the bottom piece of the Illusion tower (from bow to stern).

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I looked at the metal backing plate this weekend (located on the underside of the gunwale). I think my original estimate was 10" in length. I didn't have a tape measure, but I would say it is closer to 16-18 inches. Measurements aside, it runs the length of the bottom piece of the Illusion tower (from bow to stern).

That would be 18".

Peter

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  • 2 weeks later...

Alright everyone, here it is. It has been on for about a week and have not had any problems with it. I LOVE IT!!!!

The install went pretty easy. It was very straight forward. Measure a billion times, dry fit it once, make a template of the holes in the bottom of the base, fit template on gunnel, and drill away. The unibit sure works well. Extra thanks to Peter for all the advice. Thumbup.gif

The only thing I am slightly worried about is the strength of the gunnels where the tower attaches. I have had nightmares about the tower ripping two huge chunks out of the side of my boat. Does anyone know if the gunnels on the newer boats are any thicker or stronger than the gunnels on the 2002?? I am very concerned about this.

We did make long brackets to fit under the gunnels, as recommended. They were about 19" long, just wide enough to fit up under and be flat, and were 3/8" thick aluminum. Had to go buy slightly longer bolts to go through the plate (freekin 6 bucks for a stainless bolt!!)

Attached are a few pictures. I'll get some better ones up when I get a chance to take them (been spending my time IN the boat, not taking pictures of it).

I'll get 2 more speakers attached soon too.

Now its time for lights. Paying 500 bucks for a pair of lights makes me want to hurl. Anyone got any good ideas for this? Ive got a call into westwinds to get a price on theirs. Has anyone fabricated a some type of bracket that screws into the threaded hole on the tower and has some type of base to mount a "standard" fog light or one of the $25 lights from DIYWake??

Anyone got any good ideas for this? Or mount their lights somewhere besides the factory holes?

Thanks again to EVERYONE for all the help, support, and pointers. THIS SITE ROCKS Rockon.gifRockon.gifRockon.gif

post-1978-1184114505_thumb.jpg

post-1978-1184114633_thumb.jpg

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and one more.

Sorry the boat is so dirty in this picture!! When we put the tower on I stripped all the scum off and waxed it twice. Less than a week in the water and it has scummed up real bad already. Apparently our lake is the second cleanest one in the state too... I feel that ever since I have started using the 50/50 mix of toilet bowl cleaner and hydrogen peroxide the scum "sticks" to my boat much quicker than anyone else's even after being waxed. There are other boats on the lake that look much cleaner than mine and they have been in the water all season. Anyhow, that is a topic for another thread...

Thanks again!!

Chad

post-1978-1184115346_thumb.jpg

Edited by chadwick02
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  • 1 month later...

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