# bunk location



## doc1976 (Jul 5, 2017)

hey guys, got a question. 76 mirrocraft, ez loader adjustable trailer. the trailer did not fit the boat well enough in my opinion, so It has been lengthened about 2 feet to accommodate it better. I'm at the point of making the bunks and my question is on regard to positioning. If I place them to the outside of the strakes (I think thats the right term) then only the edge of half the bunk touches the hull because of the curve of the hull. if I place the bunks inside of the strakes it is much more flat and will have better contact and support, but I am afraid they will be too narrow for good balance side to side. The trailer also has side support guide bunks. Any thoughts?


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## Stumpalump (Jul 6, 2017)

Cut the edge of the bunks at an angle.


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## LDUBS (Jul 6, 2017)

Sounds like outside of the strakes is where you want the bunks to be. From your description, I assume you have a V-hull. It is not clear if you have long bunks lying flat or shorter bolsters on edge. If your bunks lie flat, then it is likely you can adjust your bunk brackets to the contour of the hull. Adjust them so the bunks are flat against the hull under the transom. Adjust the forward bunk brackets to the hull contour. Your bunks will likely have some twist. Just make sure you have good contact at the transom (and at the roller under the bow stem). If instead of longer bunks lying flat, you have shorter bolsters on edge, and you cannot adjust your bolster brackets, then do as Stump says and bevel the edge to match the contour of your hull. I would be surprised if you cannot adjust your bolster brackets. 

Making some assumptions here. Consider posting a photo for best responses.


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## doc1976 (Jul 6, 2017)

I guess I missed a few details in the post, sorry I was tired. It is a V hull, the trailer has been completely taken apart, added 27 inches to the rear, squared, clamped and welded back together. So the bunks are being added essentially from scratch. My plan is to lay the 2X4 bunks on their side so the 3.5 inch side will be against the boat. If I lay them outside the strakes, the rear 24 inches of the boat is nice and flat so it sits great on the bunk. however, from there the boat hull begins to curve and only the edge of the bunk is touching the hull. I intend to use 52" bunks, which utilizes the cross members added to the trailer. If I go inside the strakes, the boat bottom is nice and flat for the length of the bunks, but it puts the bunks only 17.5 inches apart on center. I guess my real question is, is that going to be too close together for stability for trailering, loading, unloading? Or will allowing only the edge of the bunk to support the hull on a portion of the bunk going to provide enough stability?

hope these pics show the situation well enough, the first two show the two possible widths I could place the bunks.


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## lckstckn2smknbrls (Jul 7, 2017)

Do both. 
The long bunks closer together and shorter bunks further apart.


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## New River Rat (Jul 7, 2017)

lckstckn2smknbrls said:


> Do both.
> The long bunks closer together and shorter bunks further apart.



Might be an option.....


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## doc1976 (Jul 7, 2017)

New River Rat said:


> lckstckn2smknbrls said:
> 
> 
> > Do both.
> ...



definitely an option. Although I would have to add another cross member to support the shorter bunk.


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## LDUBS (Jul 8, 2017)

doc1976 said:


> New River Rat said:
> 
> 
> > lckstckn2smknbrls said:
> ...



I kind of like lckstckn2smknbrls' idea. Mine doesn't have them but I see trailers all the time with short bolsters mounted just on the rear cross member. The shorter bunk/bolsters are on a swivel bracket. 

I also have an EZLoader trailer. My 2x bunks are flat and mounted on brackets that allow for quite a bit of adjustment. I included a photo below, for whatever it is worth. Just note that in order to take this photo I had to take my boat out on the local lake for a few hours this morning. It was tough duty, but I was willing to do it for TB.net. :LOL2:


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## doc1976 (Jul 8, 2017)

So I went ahead and carpeted the bunks and temporarily clamped them in each position. As I figured, the inner position is not very stable with side to side motion. I originally wanted to eliminate the two keel rollers the trailer had on it, but I think with the two bunks in the outer position and a total of 3 keel rollers it should be supported well enough. Probably overkill for a 250 lb aluminum boat, but Ive never been one to half ass anything. Once I get it all put together and painted, I will post a few pictures.


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## richg99 (Jul 8, 2017)

As long as you are at it....you might consider covering your BRAND NEW carpeting (sorry about that) with PVC. PVC 3x5 gutter downspouts, cut lengthwise, will make your launches and recovers much easier. 

But, you do have to keep the stern tied down well, and be certain to NOT loosen your bow winch strap until you have the stern over the water..... regards, richg99

https://www.tinboats.net/forum/viewtopic.php?f=3&t=40137&hilit=bunks


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## LDUBS (Jul 10, 2017)

doc1976 said:


> So I went ahead and carpeted the bunks and temporarily clamped them in each position. As I figured, the inner position is not very stable with side to side motion. I originally wanted to eliminate the two keel rollers the trailer had on it, but I think with the two bunks in the outer position and a total of 3 keel rollers it should be supported well enough. Probably overkill for a 250 lb aluminum boat, but Ive never been one to half ass anything. Once I get it all put together and painted, I will post a few pictures.



Doc, my understanding is the boat shouldn't be in contact with all three keel rollers. Instead support the boat with the bunks and the forward roller under the bow. If the bow has a reinforced section, put the roller under that. If the other rollers are desired to help guide the boat onto the trailer, my boat's manual says to leave at least a 1" gap between those rollers and the keel when the boat is in towing mode. 

For light boats like ours, I'm not sure long bunks are needed and they may even cause problems if the fit is poor (I think that was your original concern). My boat mfg says a short bunk or bolster of at least 3' that is in full contact with the transom and the flat part of the bottom of the boat is sufficient. Obviously, the bunks/bolsters should be placed so the boat isn't resting on a strake.


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## doc1976 (Jul 10, 2017)

LDUBS said:


> Doc, my understanding is the boat shouldn't be in contact with all three keel rollers. Instead support the boat with the bunks and the forward roller under the bow. If the bow has a reinforced section, put the roller under that. If the other rollers are desired to help guide the boat onto the trailer, my boat's manual says to leave at least a 1" gap between those rollers and the keel when the boat is in towing mode.
> 
> For light boats like ours, I'm not sure long bunks are needed and they may even cause problems if the fit is poor (I think that was your original concern). My boat mfg says a short bunk or bolster of at least 3' that is in full contact with the transom and the flat part of the bottom of the boat is sufficient. Obviously, the bunks/bolsters should be placed so the boat isn't resting on a strake.



interesting. I dont see how more points of contact(support) could be a bad thing. As I see it, I would be combining the features of a roller trailer and a bunk trailer. unfortunately, due to the suspension bracket set up I did not have too many options as to the possible location for the cross members and subsequently the bunk mounting locations. I dont think I will use three rollers though, I will use the front bow support and possibly one more at about the area of the front of the bunks to add a little support where only the corners of the bunks are touching the hull. I included a photo of the trailer the way it was when I picked it up.


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## LDUBS (Jul 11, 2017)

Rollers aside, those bolsters on the "before" trailer image are what I'm thinking you should use. Put them out as wide as possible but not under a strake. Make sure the transom is 100% supported (I sound like a broken record). 

BTW, The job you did on modifying that trailer is very impressive.


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## doc1976 (Jul 11, 2017)

yeah the bolsters for some reason never gave me a feeling of security, kinda just flopping around with their one little attachment point. with the way the trailer was, there was around 10 inches of boat hanging off unsupported. Also one reason I went away from bolster style was I wanted the trailer frame to meet the rear of the boat in length so I had good tie down points as well as a place to attach an outboard support for trailering. Bolsters of that style need to be mounted in the center, and that would leave the bolsters sticking out way behind the boat. One of the lakes I go to around here is a slow narrow bumpy drive several miles in so I cant have anything bouncing around. But in actuality, now that i really look at it, the way I am setting it up as really not so different as it was when I got it. Only exception being the orientation and mounting points of the bunk boards.

And thank you for your compliment on the work. I believe plenty of planning before you start, along with many evenings of staring at the project with a beer in your hand will always yield good results


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## LDUBS (Jul 11, 2017)

Aha, now I see how it will come together. You are going to have a nice set up. 

I hate rough roads. I think my boat is fairly well supported but boat and trailer are still relatively light and it bugs the heck out of me watching them bounce around.


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## doc1976 (Jul 12, 2017)

thought I would post a few pics of my progress so far.......... still have a little finish welding to do, but add lights and wiring and paint and I should be done.


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## richg99 (Jul 12, 2017)

Looking good.


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## Tinny Fleet (Dec 1, 2017)

One solution I have found while trailering a light boat on back roads is to increase tire size but air down. 

On this particular trailer I see it has 12" rims and tires, but liiks like plenty of clearance for 13 and maybe even 14" ers.

There are also shock absorber kits that you can buy online.


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