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So last week my overheat alarm started going off and so I decided to lower the mast this weekend and pull my boat out. Its been about a year since the last time I used my trailer and hauled the boat out...almost had forgotten how to do it. Its about a half a mile ride through a couple canals to get to the closest ramp. I started the motor and cruised at about 1600 RPM to get the best cooling...water is coming out of the p-hole but not at the pressure it used to have once upon a time. I got to the ramp without the alarm going off but when I got there and had to lower down to idle, the alarm started going off again.

My wife had a hard time backing the trailer in since she was out of practice too. She probably should have put it in a bit deeper since the front v bunk was just barely out of the water. By this time, I just want to get the poor misbehaving motor out of there. Of course, I usually empty the ballast before docking but with the overheat problem last weekend, I left the ballast in and then forgot about it this weekend. That puts the bow much lower than usual and I wasn't thinking. I drove the boat on super ultra slow like I usually do and the bow basically just pushed and rolled the bunks off nice and slowly. Can't go back..motor is overheating, so about all I could do is get out, put the car in as far as it can go without drowning....and then lift the bow up while my wife cranked the winch. The boat is sitting on top of the rusty metal that held the bunks on. Of course I didn't do any Mac bump and just drove it slowly over the speed bumps during the half mile ride to my house.

So I got the rig onto a slab next to my house where I can work on jacking it up. I had wanted to service the CB and paint the bottom anyway so I guess this is my chance. I haven't done a good inspection of the metal that holds those bunks on but I expect it is pretty rusty. I always tried to spray paint there but when I got it, it already had 3.5 yrs of rust and although other parts of the trailer look good, that area under the bow bunks has always been rusting away despite the spray painting I've been doing.

So now i need to decide whether to try to repair the original bunks or maybe just get a grinder and cut all that crap off, paint the bare metal, and then install some sort of V roller system up there instead of the front bunks. Other than this area, the trailer is not that bad so I would like to keep it going for a few more years on a small repair job. I've seen Duane's extra roller that he installed in addition to the bow bunk but I don't know if I've ever seen someone replace the v bunk altogether with rollers on the stock trailer. Anybody ever done this?

IMO rollers with no bunks would be a mistake. The bunks provide additional friction, so that when you hit the brakes, the entire weight of the boat isn't being held back only by the winch post. I don't think the winch post is up to it.

Dimitri,

I don't know the answer.

Fortunately, you're in an area with a lot of trailer shops. Try to get recommendations for whom to go to.

Explain your problem. If they feel a 'roller' bar could be made substantial enough to hold the weight and substitute for the bow bunk, add Chip's concern about it cutting down on the friction to allow the inertia of the boat to smash the back end of your tow vehicle in.

Hopefully you can get the overheat problem solved so you can rid the trailer of the dang Mac.

Dimitri, Inspect the entire trailer for rust. You may find other problems and need a new trailer. The Mac trailers may only get about 2 years around salt water before the need to renew. Galvanized may last 5 years.
That is what my dealer told me. Please let us know what you find out.

Thanks for the responses. Today I took a better look at it and I guess it would be nice to have the v shape of the bunks to guide the bow in. I had just been thinking I would get a welder but maybe I should take it to a trailer shop. It is already about 5.8 yrs old with mostly saltwater use so I guess I'm doing ok...I don't want to spend much money otherwise, I may as well get a new trailer. I was holding off with a new trailer until I get a truck to pull it with too (figure a new trailer with dual axles, etc. will weigh several hundred pounds more than the stock trailer). I kind of like the stock trailer with its ladder and low loading. I guess there is always the risk it will rust through and drop the boat on the road although I've never heard that happen to anyone here. I try to keep it somewhat painted so as not to let the rust get out of control.

As for weight, there is not much on that front bunk. With the bunks gone, the boat is actually hovering a couple millimeters off of the metal. I can push up with a couple fingers and it will get up a bit higher so its nicely balanced on the rear two bunks. I would expect that the majority of the friction is in those two bunks also since a very small part of the hull contacts the front bunk. I suppose the best solution would be to fix the bunks *and* get a roller. But I'll ponder how to do that for a while as I deal with the motor instead.

I got the lower unit off today and pulled the water pump out. My old impellor (3-6 yrs old) did not look all that bad. A tiny bit worn at the ends, hardly noticable. This is a bad thing as I was hoping it would be torn up and the obvious culprit of my overheat problem. I'm starting to wonder if I have a blockage somewhere else. The new impellor is much lighter as it has a plastic hub instead of metal like the old impellor. Oh well, a lot of funky gunk in there so it needed to be taken down. The service manual says to replace the thermostat every three years like the impellor so once I figure out where that is, I'll replace it too.

Interestingly, while I was browsing the shop manual, it says to never run the motor when you are flushing it through the hose fitting on the engine (effectively back flushing through the p-hole). It says its okay to run the motor when you are using the ear muffs though. I guess I have been doing it wrong since I have been running the motor with the backflusher attached although there was certainly not serious impellor damage or anything like that.

Well, I *finally* finished with my motor. Did a bunch of well needed spot lubrications on it as well as rebuilding the water pump and changing out all the lubricants. Hard to believe it is almost 6 years old now. (2000 model year manufactured in 12/99)

Got the boat supported on 3 wood blocks so I could pull the trailer out today. I must have knocked 3 cups worth of rust debris off of those horizontal metal pieces that the front bunks sit on. It makes me a bit nervous as the good metal is down to about 1/8 thick. I suppose the original was 1/4. The underlying structure still seems good enough though so I just drilled out the bolt holes and will re-install the original bunks with some galv bolts and wide washers. But first, it was a coat of phosphuric acid and then some rust oleum primer...will do another coat or two of glossy before installing the bunks back. If it breaks again, it will be a welding job for sure. I'm trying not to put too much money into this steel trailer since it has a limited life. I sure like the ladder too and so far, I don't think I've seen anyone get a non stock replacement with a similar ladder. So thats why I want to keep it going longer. Plus, I wonder if some of these replacement trailers make the boat sit higher for harder ramp launching.

As far as only 2 years in salt water though...I believe that is a bit of a stretch. When I got mine, it was already 3.5 yrs old and had never been maintained. I've been spray painting all the rusty areas every year or so since then and I expect to get 10 yrs out of it hopefully....4 more to go. Florida is probably the hardest environment on a painted steel trailer so I'll bet you can get even more years in other areas.

I'd like to put a bow roller on like on Duane's but those wide ones are pretty pricey at WM. I would put it at such a height that if the bow bunks break off again, it will fall on the roller instead of the frame. The roller should absorb the side loads that the bunks have to endure also. The bow sits a couple inches lower with full ballast and that is low enough to cream the bunks. Anybody know where to get a wide roller at a good price?

What motor do you have?

When I serviced my Honda 50 I was surprised at the amount of salt buildup around the thermostat. This buildup could reduce water flow or affect the thermostat opening.

I have the Merc BF50 4stroke. I replaced the thermostat and removed and cleaned the zinc anodes. I also had a lot of salt buildup and used a screwdriver and some saltaway spray to clean it up. The anode covers have a very slight slow leak now but I figure it will stop soon enough when it gets gunked up again.

Had the boat out for the first time in eight weeks over the weekend, and it being the end of the season and me being the only person in the parking lot, was able to leave the boat tied to the ramp dock while completeing some much needed bunk repairs.

One of the short front bunks had disintegrated, and one of the intermediates was held by one bolt only; the "replacement" front was being held in place (not very well) by a tie wrap until I could get a chance to drill out the old bolts.

It appears the original bunk bolts are 1/4" flat head mild steel; no evidence they were even galvanized. I'm a frequent defender of Mac's tendency to go cheap, but this "savings" is unconsiconable. Because of their location under the boat the bunks never really get a chance to dry out, so the bolts are essentially subject to constant immersion. I'm amazed they lasted the five years they did, probably only because my boat is mostly used in freshwater.

I took the opportunity to replace the 1/4" bolts on the broken bunks with 5/16" galvanized carriage bolts, lock washers and galvy nuts. It means drilling out the holes in the trailer and counterboring the heads in the bunks, but I believe this is cheap insurance. I looked at stainless carriage bolts, but at $1.20 apiece (X16) it's probably not justified that the bolts will outlast the bunks and the rest of the trailer.

Because of the time factor I only repaired the broken bunks, but I checked and the rest are wobbly and due to go any day. Once I get the boat in a slip in the spring, I'll pull them all off and repaint underneath before replacing them.

One plus. The staples used to hold the carpet on the bunks are stainless, shiny as new.

Yup, I agree with you on that one. My bow bunk bolts had rusted through to little thin threads. I also had the same thoughts as I was looking at the bigger bunks but I'll probably not spend the time fixing those unless they actually break off. I'm using 1/4 x 2.5 galv carriage bolts with big washers and lock washers. I'll counter sink at the original bolt holes in the bunk so as to get the head of the new bolt below the level of the wood. I'll probably pay more attention now to washing down the bunks with fresh water after launching in salt water....but this trailer has a terminal illness that can't be cured... I'd like to have a double axle aluminum trailer (with a custom bow ladder)..and a big SUV to tow it with!

I figure as long as you're drilling out the old bolts anyway, the cost to upgrade to 5/16" bolts is a close to zero as anything. I've already bought and cut to length the new PT 2 x 4 bunks, so if they need to be replaced early I'll only have to drill the holes once.

The old carpet is starting to wear through in key places and should be replaced. The only question is whether to splurge for the special "MARINE BUNK CARPET" (read expensive) $40 at WM. Seems like a lot; not sure it's worth that much more than say, standard indoor outdoor carpet. Certainly the stuff that's on there now doesn't seem that special.

When my winch post and ladder were pretty much totalled this summer in the accident, I made it clear I wanted the repairs to duplicate the old setup. The repaired post and ladder match the original perfectly. If you're in the market for a new custom trailer, with the original as pattern it shouldn't be difficult at all for a reasonably talented fabricator to duplicate it in any material for a few hundred $$. The only problem I can see is if you're trying to modify an existing trailer which is already galvanized, getting the new stuff welded on and regalvanized might be kind of expensive.

Chip Hindes wrote:The old carpet is starting to wear through in key places and should be replaced. The only question is whether to splurge for the special "MARINE BUNK CARPET" (read expensive) $40 at WM. Seems like a lot; not sure it's worth that much more than say, standard indoor outdoor carpet. Certainly the stuff that's on there now doesn't seem that special.

This may be one of those rare examples where that word, "marine," is used advisedly. That's not to say the cost is truly justified . . . .rather just that the material could be notably different. I recall reading that other carpets, in concert with the wooden bunk, can trap moisture & possibly induce osmotic blistering. Purportedly, marine carpet material will not do that.
Don't know if it's true, but I'd be studying it carefully.

I've heard that putting pressure treated wood against steel will cause the steel to rust because of the chemicals they use to treat the wood.
Anybody know if this is true?

Bill at BOATS 4 SAIL wrote:I've heard that putting pressure treated wood against steel will cause the steel to rust because of the chemicals they use to treat the wood.
Anybody know if this is true?

Ive heard of this as well ,Bill. I work in construction apparently wood is treated with a different formula now (started about a year ago I think ) they refer to it as ACQ. Really smart when you think of it,inventing wood that eats nails . When we build with it now, we use hot dipped galvanized nails, or for our nail guns we can now buy nails that are ACQ resistant ( at 4* the price ). Any metal that comes in contact has to be galvaized or powder coated. This is in Canada , I'm assuming the USA is the same. Hope this helps

Bill you are correct, PT wood (Pressure treat) is corrosive to metal. But it depends on what type of steel it is in contact with. Bare steel will corrode the fastest while SS steel the least with HD steel (hot dipped) in the middle. The quality of the HD steel will depend on what specs are used. The grade is based on the amount of zinc per square foot of surface area. The minimum Industry standard for the US has been G60 but other parts of the world conform to G90. G60 = .60oz zinc per/SF surface area.

Typical preservatives used in PT wood are: Chromated Copper Arsenate (CCA-C), Alkaline Copper Quat (ACQ-C, ACQ-D, ACQ-D Carbonate), Copper Azole (CBA-A & CA-B) and Sodium Borates (SBX/DOT).
Trade names include: Wolmanized Natural Select (Copper Azole),
Preserve and NatureWood (ACQ)
Advance Guard (Borate).
Testing has shown the newer ACQ-C, ACQ-D, CBA-A & CA-B PT is ABOUT 2x more corrosive than CCA_C. So in addition to water and salt you have chemical corrosion. How fast Im not sure, it will depend on location, use and care. Unfortunate we cant flush the bunks like we do our breaks, but I would not lose sleep over the bolts. Just keep and eye on them after lunching the boat.

CAUTION: Blue hull owners, corrosion may occur sooner!

Graham